What do you do when your 500hp M5 just isn’t doing it for you anymore? You call California-based Currency Motors who, by adding a pair of turbochargers, turns the standard M5 into the world’s fastest and most powerful four-door luxury sedan on the planet. That’s right. This modified M5 delivers up to 810hp and is capable of reaching a top speed of 240mph.

For the $350,000 price tag, Currency Motors adds its own hand-built intercooler system, a full custom exhaust and of course, two huge turbochargers. In a strange move, the engineers placed the turbos under the rear bumper, forcing the charged air to run up the passenger side of the car. This was necessary as there would have been too much heat if the turbos were up front. Testament to BMW’s engineering, the SMG transmission has been left untouched.

Inside, the leather on the steering wheel and seats gets replaced with fully aniline dyed Florida crocodile in black, similar material used in the finest Bugatti roadsters of the 1930’s. Interested buyers better be quick because there are plans for only 10 copies, and at the moment the car is available in the US only.