Sorry, but I respectfully disagree. Your hand, given enough forward velocity, at a given AOA, will generate nearly the same amount of Lift in PSI(of PSF if you prefer) as ANY wing at the same velocity, air density, and AOA. Your hand is not as clean or efficient as a wing but most of the lift WILL result simply from AOA.

Stick your hand out the window, give it some AOA and accelerate to any large/heavy a/c rotation speed, you will NOT be able to keep your hand down! Even at 70 MPH (approximate rotation speed of many small a/c) on a highway try keeping your hand at a low fixed AOA, you will find it very tiresome very quickly as your hand just can't wait to fly away.

It will produce tons of lift, in relative terms, in PSI/PSF. The only thing that stops your car from lifting off is that your hand (your simulated "wing") is of insufficient square area. It is generating sufficient lift per square area all right, but the square area is too small.

If you made your hand sufficiently large and rigid, your car would lift off the ground and fly away (at first, anyhow ) the moment total lift would equal the weight of your car.