[BugsJustFindMe]

I considered this, but actually it's a bad strategy if the door is only slightly ajar and not all the way open. The nice thing about my approach is that it works no matter what. Obviously even better if the vehicle can rapidly change from reverse to drive instead of merely slamming the brake.

[vrighter]

I've thought about this further. You said it's even better if the vehicle can rapidly change from reverse to drive.

More generally, the bigger the acceleration in the forward direction, the better.

So the best solution is to reverse and crash into a wall. It would bring your speed to 0 almost instantly. Meaning the acceleration would depend on how big your inertia is, not how powerful your brakes are (and the limits of your tyres' traction).

[BugsJustFindMe]

Well yes, obviously, but then we need to balance the cost of closing the door against the cost of repairing the car. And also what if there isn't a convenient wall nearby? :)

[vrighter]

I hadn't thought of that. Yes your strategy works more reliably.