Too funny I saw this thread... I just replaced the speakers last night in my '05 450! Like someone said earlier, check out Evilution, they have a lot of info on their site. You'll have to remove the top panel of the dash and they have pretty detailed step by step instructions. It is kind of a big process but it's worth it. (After re-assemly I didn't have any left over peices!) From Crutchfiled I ordered a pair of Polk Audio db 401 speakers (4") and a Blaupunkt THB200A subwoofer that I put behind the driver's seat. Even with the seat all the way back there is room for the sub because it's pretty compact. Another option for placement might be under a seat but I built drawers for under both my seats so that ruled that out for me. One note: the last owner had replaced the stock stereo with a Kenwwod KDC-MP388, it's not the highest end stereo out there but I guess that it's better than stock. I was AMAZED at how great the set up sounds!!!