Extending warranty on F30 320d

[breezy]

My parents have a 2012 F30 320d that is about to expire its dealer warranty. They are fairly light users (<5k every year) and my immediate thought is that they should not extend it.

Before I advise them to do just that - are there any major / known faults with the model that they should be aware of? Bearings, turbos, things like that? From memory it has around 40k on the clock.

FWIW, it is £608 with no excess or £328 with a £250 excess. Only fault since getting the car has been a front window regulator.