I was offered a 4 year old G31 520D Touring with 160k km (=100k miles) which got a new engine at 130k km.

The almost new engine seems like a great thing but I’m wondering how the previous owner could have wrecked it so early and what other parts might have been mistreated. I’m about to take it to a shop for inspection before I buy it but of course they won’t find all upcoming problems.

What kind of shenanigans should I look out for?