Attention, Chevrolet Cobalt and Pontiac G5 drivers: Take off your Hello Kitty keychains immediately. General Motors is recalling 778,562 of the discontinued compacts because of faulty ignition switches that can loosen and shut off the engine while driving. Added weight on the key ring or a bump in the road, GM says, can cause the problem if the “torque performance is not to specification.”

The 2005–2007 Cobalt and 2007 G5 (the first year it was produced) are affected, including 619,122 in the U.S. The remaining vehicles are in Canada and Mexico. Dealers will replace the ignition switch at a later date, and owners can call Chevrolet at 1-800-222-1020 or Pontiac at 1-800-762-2737 to find out if their vehicles are included.

“Until this correction is performed, customers should remove non-essential items from their key ring,” GM said in a filing to the National Highway Traffic Safety Administration.

At least six people have died in five frontal crashes related to faulty ignitions where the engine—and subsequently the airbags and other safety features—shut off, according to Reuters. An additional 17 related frontal crashes were also reported.

In October 2012, GM recalled 40,859 cars in the U.S., including the 2007–2009 Cobalt and 2007–2009 G5, for cracking fuel pumps that could leak. That was an expansion of an earlier recall for the same problem in 2009. In March 2010, 1.3 million Cobalts from 2005–2010 and G5s from 2007–2010 were recalled worldwide for electric power steering that could suddenly shut down while driving.

The new Porsche 911 Turbo S is an all-weather performance weapon. But, there's another tech-packed, four-wheel drive, six-cylinder, twin-turbo coupe that'll seat four (just) and monster just about any racetrack your can throw at it. It's the Nissan GT-R, and it's the car the 911 simply has to match. Here's Ben Pulman with the CAR verdict..

Absolutely no sign of a ceasefire in the ongoing war of attrition between Porsche and Nissan. These two heavyweights have been slugging it out so long there’s a real danger Julian Fellowes will assume it’s a saga and thus write a mini-series about it. It’s a simple plot: 911 Turbo vs GT-R, pretender vs champion, set at the Nürburgring. Don’t wait too long: Ron Howard’s on the other line.

The story started way back in 1973, when Porsche unveiled a silver 911 prototype at the Frankfurt motor show, with Turbo lettering on the rear wheelarches and a huge whale-tail wing sprouting from the engine cover. The legend was established a year later when the finished 911 Turbo 3.0 was revealed, with a turbocharged 256bhp engine, a 160mph top speed, and brakes derived from the Le Mans-winning 917. After that the 911 Turbo – the ultimate all-weather version of the world’s best sports car – never looked back.

Until 2007, when a fat Datsun kicked the posh Beetle square in the nuts. Previously Nissan’s Skyline GT-R was a mythical Far Eastern machine, but when CEO Carlos Ghosn demanded a worldwide halo car it went head-to-head with the Porsche. Nissan benchmarked the 911 Turbo, and although the new GT-R abandoned the iconic Skyline name, the legendary straight-six engine and the clever HICAS four-wheel-steer system, it posted a Porsche-beating Nürburgring lap time: 7min 38 seconds (quickly cut to to 7:29 by an upgraded version).

Porsche unofficially suggested Nissan cheated using trick tyres, claiming a GT-R it’d purchased could barely dip below 8min in the hands of its test drivers. Nissan responded, recommending all owners attend one of its driver performance courses to get the best out of the GT-R. Porsche’s riposte was the facelifted 911 Turbo in 2009, with the first all-new engine in its 35-year history and its first twin-clutch gearbox. A 523bhp Turbo S followed, but it still couldn’t beat the GT-R’s ’Ring time.

Now it’s the rematch. There’s a new Turbo, and Porsche has had time to study the GT-R’s weaknesses, so the seventh-gen über-911 has rear-wheel steering, adaptive aerodynamics and a faster-acting four-wheel-drive system, while the Turbo S version (tested here) adds an active anti-roll system, dynamic engine mounts, ceramic brakes, and an additional 38bhp and 30lb ft. It’ll lap the ’Ring in 7:27 (‘naturally with standard production tyres,’ says Porsche).

The GT-R remains the GT-R, though it’s been updated every 12 months by chief engineer Kazutoshi Mizuno and his team of fanatics. Six years of tweaks are too numerous to recount, but the first European GT-Rs in 2009 had 478bhp and 432lb ft, hit 62mph in 3.5sec, had a claimed ’Ring time of 7:29, and cost £55k. And in 2013 the GT-R is £77k, has 542bhp and 466lb ft, scrambles to 62mph in 2.7 seconds, and hustles round the Nürburgring in 7:19.1 (though the obsessive Mizuno-san is at pains to point out traffic cost his test driver 0.5sec).

Turbo first, and it’s instantly clear the Porsche’s additional £64k (or £42k if you opt for the non-S) delivers a superior interior. There are buttons from the Boxster, but leather lines every surface, the 911’s seats are more comfortable than the Nissan’s tight Recaros (which perch you higher than a pool lifeguard) and like all the latest 991-generation 911s, road and engine roar is much better suppressed. Both GT-R and Turbo have 20in wheels, but it’s the Porsche that rides more supplely, plus the PDK ’box slips discreetly through gears, and there’s even a ‘coasting’ function that decouples the engine from the transmission so you freewheel in neutral to save fuel. So far, so like a Carrera.

Enough of that. Despite the turbos, the 3.8-litre engine thrums into life like a naturally aspirated flat-six whereas the last Turbo S sounded like a washing machine starting to spin in a nearby utility room. It’s essentially the same engine as before, but power is up by 29bhp, and like a BMW M5, it’s one of the few turbo engines in the world that manages a final, hard, urgent rush towards its redline. And when you lift, despite the blanket of turbo roar, there’s now the thick, theatrical backbeat of exhaust splutter.

At low speeds this car’s optional Power Steering Plus system provides too much assistance, but as the pace quickens the steering reveals itself as accurate and precise, untroubled by what few mid-corner bumps we can find on these smooth roads. We’ll ignore the gearstick because the pull-to-shift-down/push-to-shift-up format is back-to-front, and you can almost ignore the paddles too, because all the torque means third gear can amble you around town, blow away everything on a B-road, or keep apace with traffic on a fast-moving autobahn. Involve the paddles and the changes snap through with real punch at the rev limit.

And the extra tech to take on the GT-R? Porsche Active Aerodynamics (PAA) is a three-stage aero aid that inflates the front spoiler like a lilo, and raises the rear wing. You can hit 199mph in Speed mode, or there’s 132kg of downforce at 186mph in the Performance setting. Porsche says the latter is worth two seconds at the ’Ring. Here, on these tight roads, it doesn’t make a blind bit of difference to the driving experience.

If you can’t feel the wings and spoilers working, you will notice the Porsche Dynamic Chassis Control anti-roll system. Ordinarily you can sense the weight of the flat-six, feel it out behind the back axle affecting the grip and traction of the Turbo (though the engine’s location is less obvious than in 911s without PDCC) but select Sport Plus and the hydraulic stabilisers – and the dynamic engine mounts – react more powerfully and aggressively. You can feel the entire car tense, the rear end becoming tighter and firmer. Then the Turbo S behaves more like a mid-engined car, cornering flat with little hint of where the engine is.

Yet you lose the sensations of that iconic layout. The Turbo feels more fluid and natural when the Sport Plus button is left untouched, because otherwise there’s no hint of the forces at work, no real feedback that you might be about to broach the limits. It’s still hugely impressive, and perhaps the system will shine on British roads if it can showcase suppleness and stiffness, but although ultimate pace has always been the goal of the Turbo, this new one feels less and less like a 911.

I’d keep the rear-steer system though. Just like in the 911 GT3 you never feel it actively working, instead you’re just aware that the Turbo is both agile on turn-in and steady at higher speeds. I can’t think why Nissan abandoned its own four-wheel-steer system for the GT-R. There’s a load of other stuff too, including an electronically controlled rear diff, and it adds up to mean this Porsche is F-A-S-T. Each gear leaves you breathless, it never seems to spin its wheels or lose traction, and the ceramic brakes have good pedal feel and massive, relentless stopping power. Remember when Evos and Imprezas could trouble a 911 Turbo? Now I can’t think of another car besides a £200k McLaren 12C that’ll stay with it on a good road. And if it’s wet, the 12C will be left behind.

The GT-R is different. It remains an astonishing car, and even before you drive it you’ll be marvelling at the engineering. Nissan wanted a transaxle gearbox for the best weight distribution over the rear wheels, but because the GT-R is front-engined and four-wheel drive it means the torque has to come back to the six-speed twin-clutch, before going forward again to drive the front axle. It’s ridiculously complex, and because the propshaft is on the right-hand side of the GT-R, Mizuno-san introduced asymmetric suspension on RHD cars in 2012 to counterbalance the weight. There’s other meticulous madness: the tyres are filled with nitrogen for more stable pressures, and each twin-turbo V6 is hand-built in a clean room by one of four takumi craftsmen who have over a century of experience between them.

But the GT-R still sounds like they forgot to put any oil in it. It wakes with a hoarse, dry cough, and the diffs and other mechanical parts clonk and chunter and generally do their best to be disruptive and uncouth at low speeds. You immediately set the dampers to Comfort and the twin-clutch transmission to its fuel-saving setting, but despite that the GT-R still rides stiffly, thumping into cats’ eyes and skipping over lateral bumps, the gearbox clunking when you lift off.

The GT-R feels huge too, like a big cruiser rather than an autobahn crusher, like an antiquated muscle car rather than a tool to take on the 911 Turbo. It doesn’t feel like it’ll worry a Bugatti Veyron to 62mph either, or nearly hit 200mph on the autobahn, and although Mizuno-san claims he always wanted the GT-R to be this heavy for the optimum loads on the tyres, you wonder whether all that weight will count against it.

But from the first tickle of the throttle, the first twist of the steering wheel, the GT-R feels lithe and alive. The steering is heavier and meatier than the Porsche’s, and there’s more feedback too. It’s actually disconcerting at first: step from the 911 Turbo into the GT-R and at the first corner your eyes will be on stalks as you sense the Brembo brakes struggling with the Nissan’s weight. And where the Porsche would leave you oblivious to what’s going on between tyre tread blocks and Tarmac, the GT-R communicates back to you. Initially it makes you drive more slowly, as the Porsche filters out much of what can lead to fear in the Nissan, but then it builds your confidence back up as you realise it’s up for collaborating with you. Despite the reputation, corners needn’t be taken at the highest possible speed as you hunt for an emotional involvement.

The GT-R’s gearbox is better than the Porsche’s too. The leather-wrapped magnesium paddles are firm and precise, making the Turbo’s shifters feel flimsy and floppy, and the gearchanges themselves are more emotive. Same goes for the V6 engine, which snarls harder and louder than the flat-six, and although it no longer has the performance advantage over the Porsche, it feels quicker. It’s 911 Turbo fast for 911 Carrera money, and when you’re working with the weight, firing it out of corners with a little wiggle in the wet from its broad hips, it feels big and brutish and brilliant. You’ll remember every drive in the GT-R, whereas for all its speed the 911 Turbo is strangely forgettable.

The Nissan’s not perfect though. The ride is fine in Germany, but back in the UK it’s bordering on the unacceptable, so much so that you’ll be forced to back off on bumpy roads. The tyre roar is deafening too, and the only reason isn’t doesn’t noticeably worsen at motorway speeds is because it’s already so bad. The Dunlop SP Sport Maxx GT 600 DSST tyres are nearly as bare as a GT3’s Cup tyres too – perfect for setting lap times, but not for daily use.

Which wins? The new Porsche 911 Turbo S is faster and more efficient (not just in fuel consumption terms, but in the clinical way it tackles a road) than the Turbo S it replaces, but the new 911 GT3 shows up its deficiencies. That 911 has got a (better) PDK gearbox, the steering is sweeter, it’s got the same rear-steer system but is even sharper because it’s nearly 200kg lighter, and the responsiveness of the naturally aspirated 3.8-litre engine is mesmerising. At £100k it’s way cheaper than the Turbo too, and if you stick with standard seats, don’t bother with the optional roll cage, and fit sensible tyres, you could use it every day. Unless you want four-wheel drive and the most expensive 911 you can buy, an extrapolation of Carrera 4S for the very rich, the GT3 is a better car than the Turbo by far.

Which leaves the GT-R. It’s always been compromised, harsh and rough on one hand, but able to deliver an utterly immersive driving experience on the other. We’ve loved and loathed it in equal measure over the years, and if you buy one you will too, but at half the price, it’s twice as enjoyable to drive as the Porsche.

Maserati turns 100 this year and has a whole list of events planned to mark the milestone. The biggest event will be an official Maserati gathering in Modena in mid-September, but if you can’t make it over to Italy you can still take part in the celebrations with a new book that charts the history of the trident brand.

The book, Maserati - A Century Of History, is available via the automaker’s online store and is filled with articles from top journalists as well as photos, some of which have never been published before. The content is spread over 350 pages and is a must-read for any Maserati fan.

Maserati was founded in Bologna on December 1, 1914 and officially started operations two weeks later. The firm was represented by Alfieri Maserati and four of his brothers and would launch its first car, a race car dubbed the Tipo 26, in 1926.

The race car debuted with a victory in the 1926 Targa Florio, the first of multiple race wins that would include two Indianapolis 500 titles as well as a Formula One world championship. Interestingly, it wasn’t until 1947 that Maserati would launch its first passenger car, the A6 grand tourer.

For more information on Maserati’s centenary celebrations, including access to its online store, visit the website www.maserati100.com.