[Zarathust]

A slim jim worked because the wires holding the lock were exposed inside the door. An extremely cheap fix was to wrap those with a metal cylinder.

I was under the impression that this was standard for at least 15 years but since we're talking about automotive industry, some makers may not even be aware of that yet

[berbec]

Even with cars that have the lock cables wrapped, the window has enough play to wedge it open and hit the door unlock button. Most locksmiths (sample size: number of times I've locked myself out of my car) just do that as it has less damage potential than fishing inside the door.

[Domenic_S]

A slim jim worked because the lock plunger was physically connected to the locking mechanism. You could pull up on any part of that metal piece to physically manipulate the plunger, thus unlocking the door.