my garmin nuvi also just plugged into the car charge...
the first time i plugged it in, it took a while to "find the satellite" or something like that
i don't remember how long.....but once it found itself, it was very easy to use...
the model i bought is for the US - at the time it was the cheapest available on amazon.com and i wasn't interested in using a GPS anywhere else (it's silly to use them where i live - no bigger than your thumb)....
it worked fine....
however, i will say that in my opinion you should still look at a map before you set out.....i didn't always like the way the GPS wanted to take me..
for example, it was great on the way to celebration....took me the shortest route, no problem..
but on the way back, it was obvious to me that it wanted me to enter WDW by the main gate -which wasn't the fastest way to get where i was going (where you can enter WDW by the 'backdoor".....so i ignored the instruction to turn right and instead turned left (going back to WDW the same way i'd come)..
once i made the turn, the GPS recalculated and then took me the way i wanted to go...
but had i not known that, it would have taken me the round about route...
so i always checked the map first to be sure which way i was going..
the whole reason i bought it, was i knew i had to drive into orlando itself (to the medical center for a meeting) - orlando has some rather dangerous neighborhoods....i wanted something to help me navigate.....but i still looked at a map first ...the GPS was backup.....also because the signs in orlando sometimes leave something to be desired...