Because this was posted in a Facebook page, a lot of people chimed in with what they had found in old cars...
Just recently, I found underneath the glove box liner on my friends 69 Charger Dash, that I am restoring for him, an envelope with $20 in it. It was an envelope that was addressed and stamped to go someplace in the Bay Area. The car's been sitting dormant since 1989 and the envelope was dated sometime in 79.
a friend of mine found a bag of coke and casino chips under the back seat of his 66 Impala
brass knuckles in the kick panel rubbed the insulation off the wiring. Also found a bag of pot under the drivers seat.
120.00 stuffed in the ripped up drivers seat under the seat cover
Once when I drive limos I found a paper football and I figured it was just a dollar bill. A couple months later I needed one dollar so I figured I’ll use it and unfolded a $100 dollar bill. Instead of McDonald’s I went to chili’s that day.
I once found 650 one dollar bills in the dash behind the glovebox of a van I bought at Carmax.
one time i bought a 68 chevelle and there was a 10 dollar pack of quarters in the glovebox and box of tools in trunk
I bought a 77 Ford van for Parts, but there was an old metal coffee can up the seat with $800 in Cash and change in it...I paid $300 for the van...and made another $500 in parts I that I didn't need...that was a good day...