I had an old Mercedes 230TE that could be unlocked and started with any flattish piece of metal roughly the same size and shape as the key.
Once I went out to the car early one morning to find it parked up exactly where I'd left it, with 200 more miles on the clock, the petrol tank rather more full, and the engine still warm...
My family once found their car in the parking lot of the grocery store with the groceries of someone else already inside the car, and a note and contact info left on the windshield about how this person unlocked my parents’ car thinking it was theirs, accidentally loaded their groceries into the wrong identical vehicle, closed the trunk, and then couldn’t unlock it again after noticing the mistake.
