What was the outcome?

I had this (on a front mk4 golf door) and read that if you simultaneously thump the door around the lock on the outside while someone presses the unlock button on the drivers door card you might just get lucky, as 9/10 it is a dry joint on the locking mechanism circuit board.

I tried this and got in on the first whack and a week later I'd stripped the lock mech and re-soldered everything (couldn't find any signs of damaged joints) and when I put it all back I was very grateful to find i'd cured the problem! Happy days

Tom