[Sven7]

Honestly with the fenders' couple inches of offset from the body, the wedges in the door trim would have to be enormous to clear when opened. You could attach some sort of rubber fairing to the rear of the front fender to cover the gap but it's honestly nearly unavoidable.

Maybe take some common volkwagen modification techniques and make it work for aero. Many people, when lowering their bugs, need to narrow the front axle to be able to turn the wheels inside the fenders without rubbing. Now, what if you narrowed the beam and also the fenders? If the car were not too low in ride height, and maybe had some lower profile tires, you could presumably decrease the frontal area by a couple square feet. Well, maybe not the total frontal area, because the rear fenders would still be there, but you get the idea. From plan view it would look more like a teardrop and less like a deformed frog.

The rear fender could be rebuilt with a tapering front, as this would not necessitate major body modifications.