Never seen this problem.
I folded the back seats down to load some luggage on one side.
Reached destination - unloaded - and now I can't release the rear seat belt which prevents me from returning the seat to position again. The belt in the top of the seat only moves a couple of inches before it locks. The buckle is undone. I've tried moving the car, put on slope both up and down - braked hard accelerated hard in order to mover the blasted locking ball but its jammed.
Any ideas how to release it or is this a case for removal? The unit appears embedded in the seat so anyone know the process? If not I'm stuck with a three seater GT! Its the larger offside rear seat.