I'm posting here in the hope that someone who services their own car might have an idea.
My wife just drove off in her 2005 NB and, as she disappeared, I noticed a circlip on the drive where she'd been - about half or 5/8 inch or 17mm across. At a guess I'd say it was roughly central side to side and level with the seat-backs. Any thoughts will be greatfully accepted especially if it has happened before.
I think it didn't come from my car as it hasn't been parked there for a few days but it is possible.
Thanks in antcipation.