we use this on trip to Italy and Iceland and find it be unreliable enough that we use paper map and avoid this when we could . we have a earlier Nuvi -lrb- 255 -rrb- that we like , so it be not the overall brand . there be two type of problem : - it reset itself without we do anything . my guess be that when there be momentary blip in voltage , it sens the charger be unplugged and replugged , it reset itself and usually take a couple of minute to go through the Garmin screen to be useful again . the cigarette lighter charger connection be flaky enough that a device need to be tolerant of such change . -lrb- this happen in 2 rental car , so it be not a bad cigarette lighter . -rrb- the same thing happen when the usb connection in the back of the GPS be bump . on a highway the reset might not be a big deal - but when you actually need it in navigate italian city , have it stop work be a major problem . worse be when sometimes it would show a startup screen -lrb- show a icon of it connect to a computer -rrb- and it would not restart itself - usually hold the power button down would get it to stop so we could restart it , but several time it just hang . - in italian town and city , it would tell we to turn the wrong way on 1-way street -lrb- happen twice in Cremona -rrb- . more subtly -lrb- this I can understand , but it be a notable concern -rrb- , it could not differentiate between medieval street and major boulevard : it would have direction zigzag through the narrow street that be charming when you be on foot , but really should not be navigate by anything larger that a Fiat 500 or Smart car - and subsequently we would find that we would start a block from a main road that a human would have direct we to . again , a paper map be preferable .