u have stock headunit or iDrive ?
hifi ? what amp are they going to use for your sub?
I have a mono amp and kicker 12" L7 going to install soon had in my previous car, but trying to sell the 12 and get a 10" better (for trunk *******. my cousin has 2 x 12 rockford and i must im impressed it sounds so clear
11' Benz C300 4Matic Sport
07' bmw 328xi premium pkg sedan 7/12 - 5/13
06' cadillac sts v6 luxury & perf pkg 12/10 - 3/12