What can an expert do to get an accurate picture of the damage?

Who of you knows anything about this? Can an expert commissioned by an insurance company or privately commissioned by me take off the front sign of a vehicle in order to be able to look behind the license plate or behind the license plate holder? Can an expert commissioned by an insurance company or by me privately require the owner of a vehicle in a foreign vehicle to have the vehicle on a certain day and to have access to it. In all cases, I assume that a vehicle owner of a foreign vehicle will claim compensation for alleged or actual damage to his vehicle.