I currently have a AVIC-D2 with Pioneer GEX-P10XMT XM NAVTraffic and MP3 module installed. I'm thinking about selling the AVIC-D2 for cheap and just buy a cheap D3 or F900BT off ebay. Would it be just a plug and play with the existing wiring hook-ups? I'm hoping most wiring are the same so all I need to do is to take out the D2 HU, disconnect the wires on the back and reconnect to the head unit of D3 or F900BT without re-wire the VSS, XM, MP3 and GPS antenna etc.

Your help is greatly appreciated!

They use different wiring harnesses, so you would have to re-wire everything. The good part is you've already got the VSS, parking brake, reverse signal, etc. run up into the dash, so that's a little less work there.

Different antenna too. Still shouldn't be too difficult to swap in the new harness and run a new antenna