“The car is always looking for the signal. If you are close, and a hand touches the door handle, that door opens - usually only the front seat doors have this...”
Mine do not do this. Until the button is pushed, nothing happens.
Come to think of it, neither did a couple of the cars I used to have. Could be a “feature” on different models/makes. Ours are Fords, and unlock when you touch the door if your fob is in your pocket or close by. No hard key any more, just a “Start” button.