Ham, no mention of the "swing" in your video. It is much more pronounced in the double handed sweep, but it gets the pleats going in the right direction at the critical moment and the sweep is really just "batting cleanup" as we say here in America (it is a baseball thing).

The "swing" is an important component that becomes second nature over time.

As for the car, I usually get my feet placed correctly and as I raise my right foot up (for a left door entry), I swing and do a 1 hand sweep. I'm not worried so much about flashing in the car as the door blocks an views, I'm more concerned with keeping the pleats flat and not pressing wrinkles in my kilt with my hot and steamy ***!