THE SHORT ANSWER
Before mobile detailing, remove personal items, confirm property permission, make space around the car, and ask about water and power. Share existing damage and special finishes. Owners should remove and reinstall child seats themselves.
Empty the car without cleaning it first.
You do not need to pre-detail the vehicle. Simply remove belongings, papers, charging accessories, and items you want to keep. Check the glove box and storage compartments if you expect those areas to be included. Take valuables indoors.
Give the detailer safe working room.
Doors need room to open, and the location must be clear of moving traffic. Ask the property owner or manager if work is allowed at shared parking locations. Shade may be useful, but suitability depends on the service and setup.
Confirm utilities and weather arrangements.
Do not assume every mobile detailer uses the same equipment. Ask whether water or electricity is needed at your location, where equipment will be placed, and what happens if weather interrupts the work. Get scheduling changes confirmed directly.
Show the areas that need special care.
Point out peeling trim, worn leather, aftermarket electronics, loose accessories, wraps, and paint protection film. Existing damage affects which methods are appropriate. Remove child seats and reinstall them according to manufacturer instructions after the appointment.