GPS questions.
 

I'm kind of searching for a reasonable GPS with a back up camera input and found the information is all over the place. For example on the 3 models below. The same looking port on each of them but the 5100 Max and 2100 says external antenna, the 2100 Max says AV input. Are they all for the same purpose, I can either use it for antenna or av input or does it have to be specific component as listed?

Navigon 5100 Max GPS Navigation
http://images.highspeedbackbone.net/...-call04-ar.jpg
Navigon 2100 Max GPS Navigation
http://images.highspeedbackbone.net/...30-out7-dr.jpg

Navigon 2100 GPS
http://images.highspeedbackbone.net/...call04-dmp.jpg

I don't know any of those models, but i love my magellan.

What in the world is a camera input needed on a GPS.

Just got a new Garmin. Boy does it work nice.

All the new high dollar cars have a $3000 "Premium Package" that includes a GPS that will go obsolete and a back up camera. I bet he is trying to emulate this at a lower cost.

And if the literature says one input is for the 2 GHz rf and a different one is for video why don't you believe them?

The other somewhat less common use for a camera input on a GPS might be to tag photographs with lat/long. As a photographer myself, I've often thought that would be handy.

Dan