What a refreshingly balanced thread about the actions of the Old Bill. As you said, they can't be expected to know every act and section.
TBH, as long as they are as reasonable as the officers who stopped you, I'd like to be stopped more often (as long as I haven't been doing anything wrong, of course!) How else will my car ever be recovered if it's ever stolen, unless the Police are stopping cars? And, as it can be a week or two between trips, I'd rather they didn't wait until I reported it missing.