Not equivalent Simon. There are lots of things which can potentially scratch your car and beyond deliberate vandalism, someone touching it has got to be a bit low down the list and is indefensibly precious. Ask my windscreen about the stone chip black eye it's got.I think you're missing the point. Substitute 'sit on someone else's settee while wearing greasy trousers' for 'lean on someone else's dirty car with gloved hands'. You wouldn't do the former (I assume), so why do the latter?