Unfortunately, dealers are normally clueless when it comes to Nav upgrades. When I picked up my GTD, I enquired about the free 3 years worth of upgrades. I might have well have been speaking Chinese judging by the look on their faces.
Still think you are better doing this yourself, and I think that's why VW made the updates available on line. Also, don't forget, if you are upgrading the standard Navigation unit (not the Pro), then you have to extract onto the original SD card provided with the car, as there is encryption on the card that's needed as part of the update procedure. If it's the Nav pro (like mine), then any standard SD card (of an appropriate size will do).
I'd give it another go downloading personally, as one of the packages might have got corrupted.
