The drivers side window on

Went onto a mini site and according to the members on there its a common problem with the mini and one way of fixing it believe it or not is just above the door speaker? give it a bang, i thought threre's know way that will work but hey it doesn't cost anything does it, so i gave it a bang and it worked. An owner who thought that the motor had gone on his mini bought one, but before he had it fitted he thought that he would give this method a try and 12 monthes later it is still working.