These were a very common sight on the rear windows of vehicles in the southwestern U.S. in the 70s-80s. Racing legend and STP product inventor Andy Granatelli owned the chain. The “TM” decal known as the “pledge sticker” was placed on the rear window of vehicles serviced at Tuneup Masters. In the event an employee of Tuneup Masters saw someone was broken down on the side of the road, they were “pledged” to assist the stranded motorist if the vehicle had the pledge sticker on the rear window, and if the vehicle required towing, the sticker got you a free tow to the nearest Tuneup Masters. They were once a very common sight around here in the southwest, but like most other stickers they have almost been lost in time.
A big thenks to Chad for sending this sticker to us.