Here a little bit of somthing some of you may not know. So you have a cellphone with an mp3 player/ has sirius or xm radio on it what ever it plays music right?? Well if you have a cassete adapter you can get an adapter to go from your 2.5 mm jack on yourcell phone up to you 3.5 mm male end on your cassette adapter and then boom you have xm, sirius, mp3 player hooked upo tp your car stereo. If anyone is more interested go to this link and it explains how you do it in more depth.
http://sprintusers.com/forum/showthread.php?t=85707

raioshakc also sells this adapter for 30$ i think tht u plug into a cd player ipod psp or anything else of the sort. the adapter sends out a radio signal tht u can tune to on ur car, home stereo, or w/e. great sound. i forget wht its called though

-JP

I would wire it with aux jack if possible, the fm tuners sound like crap if u cant find a perfectly quiet station. and the tape adapters are not a whole lot better. but that is an awesome idea:)