I would never touch a Merc lease deal after being (nearly) stung for best part of a grand when we handed it back. It went quiet after I told them I would pay for whatever was on the collection drivers pick- up inspection, 1 piece of damaged trim, never heard anything else, disappointingly not even an acceptance that they were no longer looking for £975 from us.
They basically expected the car back in showroom condition and according to them any work not carried out by a Merc approved repairer will not be accepted.
We had all four wheels refurbed the day before pick up and they wanted £150 for each wheel as they were not done by a Merc approved technician.
If you want a Merc lease deal, factor in paint repair warranty, wheel and tyre insurance,interior treatment and anything else they offer at point of sale. Anything not taken seems to incur cost at the end of the lease.