I'm in the process of purchasing my first VX. I don't have it yet, but I have been reasearching stuff, including a rear-view camera.
Here are some links (related to this thread) that may be interesting to some folks:

LCD Modules:
http://www.qualitymobilevideo.com/184rawmodules.html

I thought the 3.5" module looked interesting. Would that fit in a modified 'fuzzy hole' insert?

Cameras:
http://www.electronics-pluz.com/acccdbwwirec.html
http://www.avelectronic.com/IRM-Camera.htm
http://www.savv.com/products_rv5000.htm

Packages:
http://www.electronics-pluz.com/secrearcamsy.html
http://www.rearviewsystems.com/voy40lcdrear.html