Back in the early 90s, my mom took me and my sisters shopping for winter clothes. After we were done (and us kids had stressed her out), she opened up the car, parked in the mall car park, put us in the back of the car, checked we put on the seat belts, and then started to reverse out of the parking space, when all of a sudden she stopped, looked visibly confused for some moments, drove back in and took us out of the car again.

Turns out it wasn't our car, just the same new VW Golf model in the same color, and her key worked for it for whatever reason. She only noticed because the actual owner had put some stuff on the rear window, which she only noticed when looking back to reverse out of the parking space.

I have no clue if VW had the same keys for all/many cars back then, or if it was a huge coincidence that the key fit well enough.

The story of "how mom almost stole a car" is still treasured family folklore :P

Did you lock your keys in your trunk and need your key to unlock the trunk release? No problem, just pull off the casing with your hand and poke the mechanism with a stick. Let's face it, car security is generally a game of rock, crowbar, towtruck.

Likewise for a huge range of years and models, all Ford commercial vehicles had the same key.

Any source for this? That's completely wild.