Are there any cheap options to convert the NAV monitor to a backup camera?

I've seen various threads on the other forums, but nothing recent.

 

not that one. but you can get an entire head unit installed from jvc or pioneer for around three grand or so.

 

Yes and quite easily. You need a GVIF unit, the backup camera (there is a nice one that mounts in the license plate light) and of course the factory NAV

Seach for GVIF on disco3.co.uk - I can't quite find the best thread, but this is a start DISCO3.CO.UK - View topic - GVIF, reversing camera and DVD installation guide