Originally Posted by bdl99

Further confusion is caused regarding the year of the cars. The US cars are labelled for the year ahead, so the current model in the US would be 2012 where elsewhere in the world (you are in the UK correct?) it would be 2011.

If you are in the UK and your car is a 2009, there is a good chance that is equivalent to the US 2010 and your Nav system does have the capability for a rear camera.

There is a way of testing which Nav system you have and whether the rear camera capability is there and it is covered under one of the FAQ questions on my website:
Backup Camera Kit - Car Kit Company

Now when you say "External video source" if you are referring to an Auxiliary video input for ipods etc then that is a completely different kettle of fish.