i have been out of car audio so long i might as well be a newbie. i am bored witht he stock system in the 5 so i am thinking i will invest some money in a new system. my idea is to run a single sub with upgraded speakers in all four doors. one question though. would it be easier to run an infinity bass link and a two channel amp powering the front doors with a new head unit powering the back. or to run a five channed or four channel amp with a single ten in the back? i think the infinity bass link is cool and it would save me some money, but i want to upgrade all four door speakers as well. any help would be great. also, what is a good head unit with decent power. i hate all those bells and whistles. i love alpines and that is all i have ever had.