Years ago when I had my ex group E E21 bmw on my way home from um interstate, um, I was a willing party to some twisty fun with a 450 sel (I think). Lots of mountain pass runs with some fast runs, clearly all within the legal limit. Ummmmm. It was years ago... etc. Went on for a couple of hours at vmax, legal vmax obviously.
Anyway it dropped back and we continued on. Stopped half an hour or so later for fuel and a top up. The merc rolled in looking very hot. Guy popped the bonnet and steam and oil smoke was everywhere. Silly bugger said it started getting hot chasing me and he kept into it until it started slowing down by itself. Probably split a water hose or similar. No idea what really happened because it was red hot and we had to hit the road again. Looked expensive.