google harmon kardon ipod... they make a sweet system - runs around 200 all told, bout a 3 hour install if you know what you're doing (5 hours for myself) and works like a champ. only problem is that you've gotta do a fm modulator version, which means you've gotta sync up your radio with the transmitting frequency (even tho its hard-wired). I love it - i'd post pics of the final install, but i'm not even kinda close to my car, won't be for the next month... hope this helps!
if that isnt good enough for you, get a new head unit. It may even be cheaper.