Mate, firstly, do you wanna edit your post to take out your name, reg no and email addy? Not good thing to post online.
Secondly, I remember something about mk5 golfs having problems with the stereo. People would turn it off, go to bed and come back in the morning to find the stereo on and playing music. Apparently, it would think you put in a cd, try to play that cd, realise there was no cd, and switch to radio. Was this related to the above or something else?