I agree, the issue is that the figures you drew (car and boat) are very much not a streamlined body. They have much more in common with the circle.This pic is from the top of the page from the "drag (friction)" Wikipedia. If I can interpret it to mean that 90% of the total drag on a streamlined body is due to skin friction (since form drag has been minimized), then I think it would be interesting to see what would happen if this concept was applied to such a body.
I wonder also what portion skin drag plays in an aerodynamic body with a larger surface area than normal, like with those solar cars, or a long fuselage of a passenger plane.
I guess I'll end up bothering someone at a campus with a college of mechanical and aerospace engineering department, to see if they can shoot down this concept and/or elaborate on it some.
For another, the drag of that conveyor belt would be many times greater than the drag of the air travelling over non-conveyored wings.If you could make the moving surface move at the same rate as the vehicle in the opposite direction, you could eliminate quite a bit (not quite all) of the friction drag on the surface in theory, but it would be extraordinarily impractical. For starters, you would likely use up as much energy rotating the surface as you would save due to the drag reduction if not more. It also would mean more parts that can break down. Also, how would you then have doors, windows, windshields etc if there is essentially a conveyor belt around the vehicle? You would have so many openings in the moving surface that the benefit would be even more negligible (or the penalty would be greater if that is the case).