After reading replies here, and doing a bunch of research, I thought I'd pass on my what I learned, and what I did.
The marks on the car are called "paint transfer". If you google that, you'll find lots of advice, youTubes, etc. Not a lot of consistency. So, I decided to go by a local detailer and ask them for advice and/or an estimate. He took a look and said, "Sure, I can do that". I asked him how he would do it, because I didn't want him to do anything crazy. He said, "I'll show you". He grabbed a gallon jug of a thick orange liquid labelled "
cutting compound" and applied a bit of it to the paint. He rubbed
very gently with something like a microfiber cloth and the paint started to come off. A bit more compound, and a bit more rubbing, and the transferred paint was gone! He finished with a polish. The area is now beautiful, like new.
The detailer told me that Tesla paint is particularly fragile, and he remarked (complained?) about such an expensive car having such a cheap (his word) paint job. He said if I ever wanted to try it myself, "Don't practice on a Tesla!".
Anyway, 10 minutes, two liquids (cutting compound and polish), and somebody who knows what he's doing, and the car looks like new.
I'll stress again, he was
very gentle. No electric buffer, no hard rubbing.
I hope somebody else finds this helpful.