As my German jaunt approaches, I'm trying to get hold of some euro maps for my tomtom one (V2) while trying to keep the cost of the trip to a minimum. Are the SD cards (preloaded) compatible with all the devices (those with SD slots, naturally)? ie would a 2nd-hand card from a 710 user work in a ONE-V2? Is it likely to need a code to enable it to work?