Thread: How do I get sound into my Sony CDX-M700R?

Right, here's the situation!

I have a Sony CDX-M700R head unit (this has CD changer control via an IP BUS) which has 3 sets of RCA's out of the back, 2 pairs are for the 4 main channels and the other pair is for the sub channel.
The 2 pairs for the front and rear channels go to a Longmill Prophet 4 channel amp and run Infinity 7"x5" in the front doors and Infinity tweeters on the dash and Sony 13cm in the back doors - The sub RCA's go to another Longmill Prophet amp (2 channel) running 2 Sony Xplod 10" subs in a self built enclosure.

The question is i'm wanting to get sound from my mp3 player into the car and wondered if anyone knew how to wire my soundcard into the IP BUS used for the CD changer?

Or would you recommend an FM modulator (i'm a bit dubious about these and heard loads of bad reports!)

Or can anyone recommend another alternative?

I've thought about wiring the player straight into the amps but how would I go about wiring 1 stereo jack plug into 6 RCA's??!!

Any help would be greatly appretiated!