I will shortly be coming to the end of a four-year PCP agreement on my ML and am concerned about the potential penalty charges I may incur for alleged damage to the car. The car will be several thousand miles under the agreed limit and I would assume that the fact the car is four years old is taken into account. However, I have read several horror stories of customers being charged sometimes hundreds, if not thousands, of pounds to 'make good' their returned cars.

Would I be able to insist on asking the dealer to check the car in advance, negotiate any work which may required, and then 'making good' myself before returning the car, rather than handing over a blank cheque to Mercedes.
Any advice would be very welcome.