Hey guys, I've just fitted my second(!) rns310. Nice little unit but on both, the nav works for about 3 miles then the whole unit resets, and keeps resetting every 30 second or so until you take the disc out....Tried another disc, same thing! I know these thing are supposed to be plug and play and don't give you a battery drain (mines a 2005 GTI) which seems to be true but maybe it does need coding? I cant believe I had 2 dodgy units!?