So I start the car this morning and the rear wiper starts. Me thinks I've pushed forward the stick but alas no. Messing about with the stalk show the wash works but I can't switch it off. 51 minutes later after driving into work and fuming from the dry wipe noise I swapped the fuse and fault remains, so fuse has been pulled. Lovely quiet trip home though.
http://www.mk5golfgti.co.uk/forum/index.php?topic=21643.0 Sounds like a common problem with the rear wiper motor