Interesting read - seems that ererybody has to learn the briefecase trick the hard way.
We are inthe fifth generation of keyless systems by now - and they are incredibly smarter and better than the first were.
By now there is no chance of tricking yourself.
My first bitter experience was is an early Audi D3 (A8 two generations away)
Filled the car up on the highway petrol station and decided to have break after that.
So parked the car, pressed the lock button on the door and at the end decided to leave my jacket in the car.
You guess?
Dropped the jacket including mobile and car key, closed the door and all messed up.
Car shut and key inside - this will not happen with newer systems;-)
Solution: smash a window and choose a sliding one as it is best for replacement.
The most interesting feeling was smashing a window of a quite new luxury car in a public car park.
A couple of stunning views - but that´s it - no problem to drive it away after....
I love the system by now and use the side morror´s dance to make sure it is shut.