OT: best buy to maintain a (maybe) driver's NCD?

Goodness knows what Merc model, I didn't look, only 2 years old. The gear selector was a little lever behind the steering wheel, like an audio control lever or cruise control knob.

I have kept the brake pedal pressed when starting vehicles from time immemorial, so it would not be noticed by me whether that system was on, same as having to press the clutch on manuals, that must have foxed a few people over the years, my dad included, he bought some crap thing like an Hyundai from someone that delivered it, dad then phoned me to get me to come over because it wouldn't start, I did and immediately realised it had a clutch interlock. Next door neighbour bought a Corolla auto and complained that he could not get it out of park unless he pressed the over-ride button next to the lever (needs two hands) Despite him always having driven autos, he was not in the habit of pressing the brake pedal when moving from Park (which of course on most modern autos has a gearshift interlock) !! I was amazed and wondered how he had conveniently managed without lurching forward or back when starting off, presumably he used the handbrake, I wondered how he would have managed if he had tried that with a foot operated handbrake, like my Lexus has.