There's a book called Stop Abusing Bernoulli that claims the popular way lift is taught in text books is incorrect and the wind deflection theory is the correct one.
However, I don't agree with your plywood example since that is more of an example of how drag works than lift. The reason it's hard to hold onto the piece of plywood is due to increased form drag as you accelerate, not increased lift. Remember, drag is a byproduct of forward motion (thrust), which is why it becomes harder to hold onto as you speed up. Impact air does supply some lift, but I don't think imagining a piece of plywood is a good way to explain it.
For example: no matter what speed you're driving before you let go, once you do, the plywood would not continue to climb higher into the air due to excess lift. It would simply fall to the ground.
Using your example, the plywood should continue to develop enough lift to gain some altitude, however, in reality, it would not.