The reason I am concerned for your safety is that you may not spot some driver in your dangerous categories. Don't expect a vintage VW to not contain a crop haired lesbian driver. A reflection from the windscreen or a too hasty glance behind you may mean you miss some vital clue. I feel you should always fall back on your fail-safe behaviour and treat all cars, vans and lorries, not to mention buses as if they were being driven by an illiterate Gujerati with a ton of crack cocaine concealed under the floor. Don't trust any of the bastards, and you won't go far wrong. Even what looks like a true born Englishman in an (here fill in name of car acceptable to you) may turn out to be a Guardian reading bonehead.