Above is how they are put together and how they come apart, at the seams. Note forward cargo door open. The Amateur Scientist was a series that ran in the Scientific American for years. It showed that a layman with ordinary tools could simulate and create the same results as expensive experiments. I have done this Boeing 747 at 300 knots and door opens experiment with a four window American sedan at 70 knots on long stretch of highway.
Air entering via the air conditioning is equal by air venting outside.
The passengers inside the car feel no wind and no pressure difference. As soon as the right front window is 'cracked' by lowering it using the electric switch, air enters the cabin and pressure difference is felt as air is pressed inside car. Even though the window is flush with outside of car and the air flow is parallel, the fast air enters cabin at high speed about twelve inches after the forward part of the window. The right front passenger is buffeted by air. The air is completely felt by passenger in right rear seat.