Bchester6

Yes it's the preamp signal you want tap.Prepare to add spacers in the front but the rear can handle a speaker with a little more depth. Whomever you purchase these from should know exactly what your going to need at time of checkout. Better to buy and not use than to not have at all. As far as tweeter size go, it's whatever you're comfortable with as the C3 may require a little modification to fit in the factory location but I don't think enlarging the trim ring is that big of a deal or requires special skills. Also, rear fill is just that, don't over think it as it doesn't make a huge difference either way. The important thing here is that you attenuate down -4db, -8db, etc. so that they do not impede the imaging created on your front sound stage. Take your time and enjoy!!

Ad_Quadratum

Awesome, thank you so much again. I'll just stick with C2's but I have a funny story, so when I bought this car in November of last year, 8 months ago, I passed up a white 07 TLS with 40k one owner and I hate myself for it. Tsx is great but I loved my 03 type s. So I posted my car on Craigslist and got a bite for 21,500 (12 SE with 60k) :o so I might have this one sold and be hunting down an 07 type s lol. But at least I know 95% of what we've discussed will apply, I'll just have to learn the ELS system's work around. But Can You Blame me?

Bchester6

I don't if that's what you want. No need for compromise at the stage of life! So the ELS system is gonna be an entirely different beast when it comes to the audio... Get to reading up on it cuz I think the HU is where all the "magic" happens and that poses a whole new set of challenges. Wish I could help more but I don't have any experience with that particular system but I would recommend utilizing this forum to get to where you want to go.