I am back in finland and the deflector testing has continued in my ID3.
This shape has worked best in the Id3. I have tried today. 2 versions of the flat plate, which I had previously, and no flaps at all. The straigth flap is still behind this curved flap. At the moment car is lowered 30mm by H&R springs. In front lowest point of that deflector is now in 80mm ground clearance. This hard 2mm abs is only for testing more flexible solution will be needed in the end.
Same/similar curved deflector at rear (can be seen at the pic) which was 20mm shorter did not work at the rear and the oem one worked better. Will test other version front and backif I will find ever better solution.