Best quality for painting

Hello together, I’m giving a new car this Friday for repair at my Mercedes dealer. A few body parts are reordered and also repainted. Now my question is: how can I get the paintr to work properly and carefully? Up to now 90% of the estimate is taken over by my comprehensive insurance, but I would like to pay more… My idea was to give 400 € tip to the dealer when the vehicle was handed over to me with the words After some research, there are several ways to paint, to stick off Another point is the interior. I’ve already experienced several times that there were scratches in the interior… How do I get out of this? Because a lot of piano varnish and leather … What would you do? Thank you in advance