A car repair shop is not allowed to issue a safety inspection unless a car is repaired there or repaired is going to be done. If the vehicle in question has been repaired in that particular repair shop or is going to be repaired there, then they are not allowed to perform the safety inspection.
If the company you are working for is the owner of the dealership, you are prohibited from writing a service inspection report unless the kfz gutachten vehicle in question was fixed at that specific dealership or is going to be fixed at that specific dealership. If the vehicle in question was repaired in that particular dealership or is going to be repaired at that particular dealership, then they are not permitted to perform the inspection.