Finding treasure: The things you find when disassembling a car

Two years ago, I gutted out 1964 Buick Wildcat parts car. I saved as much as I could that would fit in boxes, and sawed off good pieces of the body. It has been so long I don't remember where I found this, but tucked away somewhere in the body was this cup from GM that reads something to do with "POPUP" and "suggestions." I've ready many stories of what people have found in cars, and I was happy to come across a factory accessory in mine.