Finished installing the Pioneer AVIC-D2 today. Here's a shot:
Backup camera is Pioneer ND-BC1, a bit dirty but here is pic of install. I had an old sheet metal bracket from something, fit just perfect to hold the camera. Used double stick tape to mount bracket to trailer hitch and camera to bracket.
For anyone interested (or whoever followed my earlier thread), I gave up on the Neucleus adapter and went with Peripheral GMAH24B and GMAHCM. I was tired of waiting for a new Neucleus adapter, and I had a feeling that a new one wasn't going to solve my problem. I'll use it for a paperweight when it comes in.
Thanks to all who've posted info here, especially F5 for his Z1 writeup, I probably wouldn't have attempted this if he hadn't explained things so well.