I've had the car into Porsche twice since the pandemic started, the most recent time being a few weeks ago for the motor mount voluntary recall. I picked up the car and drove it home, took no special; precautions (there was a steering wheel cover on the wheel but not sure what else was done to sanitize the car). I've used the car regularly since then, no open windows no home sanitizing or precaution. I have since been tested for Covid and received a negative result and a negative antibody test. I'm not sure that this proves anything but, as said above, you have to do what you're comfortable doing. I would guess that the dealership takes some precautions but the service people are mechanics and technicians not infectious disease experts. I wouldn't put much trust in at the car having been given anything but a perfunctory wipe down.