After some extended listening, I find myself wanting more bass from my setup of 4, 5-1/4" midbass drivers. Vocal clarity is better than the stock system, but overall there's little punch, and its not a system that begs you to crank the volume. I don't want to replace the factory head unit and amp and rewire the entire car (did that on my 325i already, what a chore) so I'm hoping that having 6" drivers at the doors will give me a sound I'm happier with. The two problems I see-- and please someone correct me if I'm wrong-- (1) the door enclosures are 6.25" in diameter as I measure, precluding the use of 6.5" or 6.75" replacement drivers. (2) the stock drivers are 2 ohm rated, while most car audio replacements are 4 ohm, effectively cutting your amp's power in half. SOOOO.... Infinity's Kappa 6.07cs component speaker that mounts in a 6" location and 2 ohm resistance. Seems to solve both issues. Anybody try it, or will I be the first??