Every time this gets posted you get at least a couple of people pushing up their glasses and refuting it like they've never ridden a bike or stuck their hand out of a car window

Fair point. This was the first thing I looked at when I woke up today before putting my brain in gear, and I was thinking of the example of being in a train carriage at 70mph and jumping up - because the air resistance is acting upon the train, not directly upon the passenger jumping up and down, they don't end up having the back of the train catch up to them at 70mph...

Yes but if he jumps the same direction as the vehocle is going, depending on the angle he jumps at, the surface area he presents for the air resistance would be really small.

I considered that but I didn't find it plausible due to the "pull" on the hair at the base of the ponytail. Unless that's a very oddly shaped skull.