We received a car of a similar class, not what was specified in the booking. Clean, but not perfect (a couple of stains on the seat and it was obvious that the carpets had been vacuumed very quickly).
There were scratches on the car, all of which were already on the transfer record.
We were advised to take photos and video. And explained how to return the car.
We were told that the car would need to be washed before returning it. When I called the company and asked if there was such a clause in the contract, it was not there. After checking with the company that gave us the car, it turned out that it was just a recommendation: "if we suddenly go to the beach and the car is very dusty" - we were recommended to wash it, but not required "we misunderstood everything".
Otherwise, everything went as we planned. Returned late in the evening, left in the parking lot, threw the keys.