"dropping into a supermarket while travelling to/from our place of work, travelling in public to a meeting"
I left just over 12 months ago so things may have changed: was there really such a bar? We did this sort of thing as a matetr of course dropping into service stations etc in uniform as we travelled up teh motorway to and from Wyton/Abbey Wood/station visit etc. I almost feel I should hand my undetected crime badge back!