theres a kit you can get to hook up RCA outputs on the factroy radio. Usually you have to wire them up to speakers though, but It would be hard because we dont have them in the rear deck, instead in the door panels (freakin ford).

N S K
Nomi K.
99 red SVT
Kenwood CD player
Portable DVD
kkm intake
Dreamcast
Interior Neons
Underbody Neons