I've just switched from the Caterham road harnesses to proper 4 point ones, so seats out. Murphy's law being what it is, on putting the last allen headed bolt securing the seat to the runner back in, it starts spinning - NOOOO! Double whammy of it being the one right in the middle of the runner, so very little access to do anything.
So I've pulled the seat back out and managed to release it again, but what's the perceived wisdom on how to re-fix or replace the rivnut? At present I haven't even managed to confirm whether the thread inside is still good or not :-/
I do have a bag of the rubber rivnuts, but I suspect they're going to expand too much and foul the runner movement.