Start/Stop button with the comfort access key incident

This is an incident that happened on the day we moved. I wanted to write it down to remind myself and maybe others never to let it happen again.
Seb has a company car and has been driving it for a few months. On the day we moved to this new house, I took A2 with me in our family car to the new house first while Seb supervised the movers in our appartment. In the afternoon, he took A1 with him.

Seb has a BMW 118. Instead of a conventional key, he has a so call comfort access key. When the comfort access key comes into range of the vehicle, a touch on the Start/Stop button will electronically trigger the ignition process. When we use the car, this car key can be in my handbag and just pressing the Start/Stop button will start the car. How convenient. Another 'good' feature is that the car auto locks itself.

On this fateful day, Seb arrived with A1 sleeping in the car. He came out of the car and by reflex, closed the car door. Since there was no car key to remove from the ignition, he did not take out his car key which was sitting in the cupholder. The car was locked with the key in it. The spare key was packed away in a box. It was a hot day and we panicked. We shouted at A1 and banged on the window. A1 woke up with a start. We shouted at him to remove his car seat belt. I knew that it would be impossible as he did not have the strength to press the button. He looked frightened with us shouting at him behind the car window. He then pressed the window switch to lower down the window. Thank God it was not locked! We encouraged him to keep pressing it down. I helped him to release his seat beat and we asked him to go to the front to get his dad's set of keys. He did as we said and with that we managed to unlock the car doors. He was wondering why we hugged him so tightly once he was out of the car and all the praises we gave 'bravo', 'smart boy', 'good job'......

It was long 10mins ordeal. When Seb received the car from the car dealer, we knew we should always have the car key with us when we leave the car as this stupid Start/Stop button system can make us conveniently forget about the car key.

We are extra careful now. We always check that we have the car key with us before banging the car doors.