The rear-view camera install done at one of the best car stereo shops in the country, Sound-in-Motion in Allston, MA.
The basic setup components are:
NavTV video switching module, model BMWV+. Unfortunetley, you can't direct link to the URL, so enter 2004 330i factory Nav from the link below:
https://navtv.com
Sure, you could use the OEM TV tuner, but this is actually easier, has a warranty, SIM installs them all the time, and they are rock solid. Plus, they're basically plug and play with the MKIV. $250 for the camera, $350 for NavTV module + about 4 hours of labor. Total cost was around $1100. And totally worth it.
That video module will be used to tie into a reverse camera. There are many cheap options out there, but I like the wide-angle of the Eclipse BEC-108.
http://www.crutchfield.com/S-yLLJGyf...se-BEC108.html
You need a skilled shop to cut this into the car properly. I have them mount it above the license plate and angled down slightly. Looks better than the OEM solution which replaces the trunk release button with some silly button / camera combo thing. Also much better quality than those $hitty keyhole cameras. The camera of course will be tied into the reverse line on the car, so when the car switches to reverse, the Nav screen will be overtaken with the camera automatically...