have you tried the relays, sounds like the symptoms of that "problem". Most people seem to have the cutting out problem on here. I dont know much about it, but i think it is relay 30. search around the mk3 forum for the topic about changing relays. I think the hall sensor could be the problem too, but not sure.LL
Relay? like unplugging a plug - dead easy But like has already been suggested, see if you can get the fault codes read for starters - this might give you some pointers