main beam will not stay on when switched....tried fitting new switch but problem still persists. I'm guessing there must be a relay involved somewhere but haven't a clue where it might be, anyone any ideas please? My local VW dealer won't help!! Thanks.

I'm not familiar with European models, NA models don't use a relay. Therefore if it's remotely the same I would suspect the dimmer/flasher switch is bad (the one on the steering column).