I have a Sony head unit with RCA inputs in the rear, and a 3.5mm jack in the front. The RCA's in the rear have a bluetooth receiver plugged into them. As soon as I turn on my car, the connection is instantly activated and every sound from my
N95 is routed through my car stereo's sound system.
Before I got that bluetooth receiver- I had just been plugging the
N95 into the 3.5mm jack on the front of the stereo. Worked great.
Don't forget- it's not just sound from music and video (yeah... I watch episodes from the first couple seasons of the West Wing when I drive around. That's a cue for someone to tell me all about the laws ;) ) or your navigation software- it's for phone calls too! The bluetooth receiver I have has a microphone input- but of course a 3.5mm cable doesn't usually- the
N95 is smart enough to realize this and enables the phone's microphone while using the car stereo as the speakers for the call. Brilliant.
And you don't need a special cable designated for MP3 or CD players. Any 3.5mm stereophonic cable will work.
Or you can get an FM tuner. I'm surprised that someone would recommend an FM tuner when better options exist, then go on about being serious about sound means you have an iPod hooked up to your car stereo. I'm not trying to start some crap, I just found it a bit amusing.
Anyway- whatever you do, don't use an FM tuner. You're getting a new stereo- so don't even count this as an option for you. I used one until I had the ability to hardwire my music to the car stereo. There is no comparison between fm tuners and a straight cable.