Hi,
searched for the failure of the left seat. It moved a bit forward while braking - this drove the Mrs crazy!
I did not realize that - a question of body-weight...
As it didn't slide forward by pulling the back I thought this was only on the right side possible
So put all the covers to the side, compared both seat rails and the mechanism - no difference at all apart from moving when fixed and not moving when released...






Before replacing the whole seat I tried WD40 in a drowning dose and then this impression appeared:

Something seems to have stuck there for ages - now it is rusted away / gone.
And the seat moves as it should. And is fixed in the driving position. I assume, it has never been before...
