In 2012, pre GM SLP program, our Service Manager asked us to participate in a Car Clinic on a Saturday. It was held from 9am-1pm and advertised as offering free coffee & doughnuts as well as a free 27 point vehicle inspection. Of course we were skeptical as to the outcome, but came in to help out.
We put together 3 teams of 2 people, whereas the technician would rack the vehicle, and begin the inspection, the other person would get the VIN, mileage and customer's information. Techs would tell the "writer" person what he felt needed addressed and how urgently, and the Service Manager would speak to the customer to let them know we would call them with an estimate on the repair(s) if they wished. The writer would make sure any parts needed were priced out, then give the inspection to the Service Advisors to quote the job, and call the customer.
We received about 30 customers or so for inspections (who knows how many were in for the free doughnuts

) Some did not require anything, some required a lot. What I found most interesting is, nearly all who were quoted, came back in for most, if not all, the repairs recommended.