Yes I think I did see an XML file somewhere but I'm no programmer and have no intention of trying to be one. I get frustrated very easily with buggy half baked software such as that which Garmin apparently is more than willing to foist upon an unsuspecting public.
Actually it really should not be necessary for me to be a programmer and do what is their job as I paid for the privilege. This is clearly Garmin's responsibility as they assumed total control over the upgrade process and the unit with their web updater program. It queried the unit's model and serial number up front so it should have known well ahead not to proceed and not to lock the upgrade to what is clearly an incompatible product. Then to deny a refund.
All I am trying to do now is to get the unit back to were it was before it was broken which they say they will do with a DVD. And then to receive a full refund for the useless to me lifetime upgrade product which is obviously incompatible with Nuvi 500s. At least is is with mine.
As I said, while it may indeed be a great thing for some, as I thought it was going to be, it is most definitely incompatible with Nuvi 500's. Not if you want to retain the full functionality you had when you bought the unit. If you want to turn your 500 into a rather crappy, very limited and feature poor street only unit then fell free to forge ahead.
Offhand I don't know how many other models it affects but if you want street maps, currently running at about 1.3 GB for the lower 48 and 100K topos, apparently now at 3+ GB of memory, as their program indicates and unless your unit has at least that much free memory available, I would advise you to steer well clear of Garmin's Lifetime update.
While I suppose you could put the 100K topo on an SD card, that would then occupy the one SD slot I'm now using to 24K topo data away, which I do not intend and simply will not do. Plus as I said to see contour lines on your 24K topo maps you also need to have the 100K topo map installed too. Not very cool IMHO.
At the rate they are going, if your unit isn't incompatible now, it may well be in the future . As I said the total data space required has now increased to be about four times the size it was in my original unit.
I suppose lifetime means different things to different people. To them it seems to be a limited amount of time indeed. All I am saying is to have a good hard look before you take that leap.
BTW I just tried it in street navigation, as that's all I have right now and if anything IMO the voice guidance is now worse than it was. There is a lot of useless chatter without anything meaningful to say. Lots of repeated instructions but none of the approach to turn guidance "in 300ft. turn left" as the old software provided.
Forewarned is forearmed. I'm just sayin that if you have a 500 you really do need to watch out here.
Is there some reason you are unable to restore the maps on your nüvi 500 from a backup archive?
Does this model have a GarminDevice.xml file in it's Garmin folder?