If you are talking about the FM modulated cd changers that use a wired remote control to broadcast the cd to the antennae, don't bother. It is the cheapest way to add a changer to your car, but sound quality is pretty poor. Think about the way the system works. Sound quality can never be better then the kind you get through FM stations.

I wasn't even satisfied with direct wiring systems, where the changer is wired into a separate channel to the head unit. I went with a true-digital, "fire wire" optical fibre output cd changer made by Alpine. That, made a difference.