usually in checkpoint use a mirror to check cars ,but instead of that if we use a robot mobile equiped with wireless controlled carridge to check the bottom of cars and send pictures and data to a remote computer or to mechanic reperance center ,in that way no need to introdude of warker underneth the car,also use this mobile to escape from alowance during driving a car by making conversation with it or asking about something you dont know stored in mobile robot database or the robot search it through internet to give you the answer .