there were quality assurance people who would randomly inspect certain areas on a car as it went through the assembly line process.
when the cars were assembled the workers would sometimes put inspection marks on nuts/bolts/firewalls, engines etc.... to show that they checked there work (i.e. being sure the nuts were tightened/torqued correctly).
maybe the secondary tag was a QA person who examined the car when it was all assembled at the very end before readying for shipment to a dealer
