OK, I'm asking this out of curiosity and because I have seen people advise that dealers should always supply the sat-nav DVD with their car.

I subscribe to a speed camera database that I wanted to put onto the RNS510 system. I needed the original map disk which I have, and have now added the speed camera info, plus a few other POI's such as ANZ locations etc. Anyhow, I then found there was a limit to the number of POI's the map could show, but that's fine.

However, it obviously installed the new info (and presumably the map) from the new burnt DVD that I provided? Thus, I'm just curious as to whether the DVD is actually linked to the car's unit, or could you theoretically share the DVD with others with the new maps?

I know that every time there is an update to the camera's (which is weekly in my case) I should have to create a new DVD which could be rather expensive. But I just wondered how the DVD, if it is, is linked to the system?

The dealer told me that I should 'ensure I do not lose my map disc as they cost $1,000 to replace'.

A short time later she said when new maps were available, if I bought the car in they would upload these to my HDD without charge.

Thus just curious how it works?

Thanks