Hi, I purchased a 79 Dodge D150 from a GSA auction in Kansas City, MO; early 90's. It was low miles, had a good body, and apparently was used for painting/maintenance from the looks of the truck bed. Three months after I purchased it, needed auto trans rebuilt, but otherwise performed well for the time I owned it, nearly 6 years. I think the low miles belied the stop and go, short mileage trips of a maintenance truck at the GSA complex.
Former FBI Camaros got bid up real high, and I am not sure why.
Before we purchased this truck, we had gone to other auctions and noticed that the good looking vehicles were bid up past high blue book. Many people at the time believed that the vehicles got regular, scheduled maintenance, and if they didn't look well-used, got bid up high. The only guarantee at these auctions is that the car will run as it crosses in front of the auctioneer. If not, it is noted in inoperable and a general statement of what they think is wrong is generally provided.
Overall I would rate our experience satisfactory, but you are limited in looking at and are not allowed to road test a vehicle before purchase. It is also cash/certified check or money order on the barrelhead within 24 hrs of sale.
Hope that helps out.