My previous car's locking system malfunctioned one day outside of preschool last year and locked inadvertently when I shut the door. It wasn't something that should be able to happen, DD was in the back seat and I was in the car park in the sun. Luckily, my DD was old enough and followed my instructions to get the keys out of my bag and unlock from inside, while I was on the phone to the roadside assistance people. But I was a bit freaked out that the car could do that!

I guess the warning is that even without auto-lock enabled central locking is still reliant on a computer system and there can be an issue arise out of the blue! Mine had to be fixed (under warranty, thankfully) by the manufacturer.