I bought my truck from CL two years ago and when I removed the inner door panels I found 4 brown rectangular packages all taped up. I had a look inside but all that was there was a green flaky sort of material. I tossed it all in the garage.
I found a receipt from an Arizona police impound yard auction sale, the truck was in there at some point for something.
Just kidding! Nothing crazy in dad's old truck, I assume the ash tray is full of coins from the 1980's and early 1990's, we paid cash for gas back then.
I did find one of those "emergency backup key" hidden boxes on the OEM radiator core support I bought from the parts forum here back in 2013. No key though.