Went to the car this morning. Saw a lovely 1 inch scratch on the edge of the front bumper. Driver's side. Can see the black base. So very annoying. How and when it happened I don't know. Might have been the dustman on Monday as it does not look like parking damage. I had a premonition that this type of baptism would happen. It could have been worse.
No pictures, sorry. Car is at BMW for a smart fix. £100 cost. Will collect it on Saturday, even though it will be ready for tomorrow. Also, bought some touch-up for £24.50.
Unfortunately, one has to be stoic about these things when living in crowded London.