well here is a system that i built myself and pieced together and just want to share some of my tricks if u have a stock stereo go buy the single din conversion and the harness i paid twenty for both and love the sound alot better plus my CD's don't skip as much just on hard bumps u can buy the harness to control the radio from the steering wheel but after a month u wont even notice no i got a base model 5 speed w/ Manuel widows and i would suggest that too i can reach every on to roll up and down and wont have to replace a motor. but the most problem i had was with my 08 3 the plastic above the back seat always vibrated so i bought a can of GREAT STUFF its expanding foam and works wonders i only opened the covers and put it under the plastic there and it got rid of it as for the trunk well i havent found a permanent fix but im still lookin