I also touch it to make sure the 5G is calibrated correctly. The 4 rotational antennas on your wheels manifest a signal to the left rear of the car, since almost all the cars here are left-side driven. It uses the driver's body as a signal enhancer. If I touch the left rear of the car and don't get a small electrical charge to indicate that the 5G is appropriately reporting, then I have a buttload of paperwork to fill out later.