Hi, I struggled to find any relevant information on this issue or clearly related to the issue I experienced so hopefully this may help someone in need. Sorry for the self answering post.
Issue/situation:
Gearbox moves into drive, parking break releases but car doesn't pull away. Feels like the car is rocking, rear breaks seem to be stuck.
Car was taken to a car wash the day before and parked on a step hill. Parking break engaged strongly.
Solution:
Throttle down hard unstuck each of the back wheels in turn. Careful as obviously the car will jump forward. There was a loud, almost cracking noise as the breaks released.
No damage to the break discs evident, function as before.
Has anyone experienced this before? I was tempted to spray the discs with WD40 but that seems quite mad.