The "no-mar" gap and flushness gauges from Assembly Tool Specialists Inc. are used in the majority of the auto OEMs as auditing gauges to ensure that none of the fixtures that determine the gap sizes have loosened during the assembly process. In the body shop, they can be used to set the gaps during the assembly process to return the vehicle to its original condition. The flushness gages can set the sheet metal variances also. See videos on the company website.