Pls help me out on this. I'm getting mix advices from dealers and audio retailers on the kind of cd changer and adaptor that would work perfectly with the standard Symphony head unit that comes with the 2000 A4. I'm more concern on the model or maker of the OEM adaptor.

If you get it from Clair Parts, it already comes with it and plugs right into the car. Same thing if you get it from any other Audi dealer since it is OEM. But if you buy it from Autotoys.com or Crutchfield or somewhere, then you'd need to get an adapter from the changer to the plug in the car. Don't remember what the model number is exactly, DP601 or something.