I noticed that this area is pretty dead so I thought I would try something I have done in other forums in the past. So what have you done to your car audio in the area of audio? In my 2009 MCS with HiFi option I have changed out all of the interior speakers with MB Quart. Front tweeters are now crossed over at 5khz 12db, original 6db filter was about 8-10khz, front 4" are now crossed over at 100hz 12 db as well. The 6.5's are running the stock filtered lowpass output from the amp. I have upgraded the sub stage with the Urban Mini Enclosure with a custom Made Team PSI 10" sub with a DD SS1a amp pushing it. The goal of my install was sound quality and the ability to have some good bass when I get the itch. Tell me about yours!