I owned a 2-seat Mercedes 380SL sports car. At 66,000 miles it threw the timing chain. Ruined the engine. No recommendation in the owner's manual about it.
Dealer quoted $7,500. I researched and found the "450" engine used to have a double row timing chain but they changed to single row to save weight when changing it to a 380. After that, lots of reported problems.
It was out of warranty but Mercedes of North America paid half. With urging by me of course.
After repair, I sold it. The other beef was brake jobs. That vehicle recommended a brake job every 10,000 miles. And it was very expensive to do those even if you didn't use the dealer. The brakes were fantastic-- but not "that" fantastic.