Weird black shadows

Hello!
I have a problem with black shadows appearing on my car.

https://i.gyazo.com/6ba7ffc7f8b1b87ec00495c1521602a7.png

If i remove doubles it gets worse

Sorry if it looks weird, it is A okay, just need to find a way to remove the black shadows.

You have bad topology.

Recalculating normals would fix it in normal circumstances, you would need to clean up your mesh first in your circumstances (though i advise starting over from scratch)

I’m suspecting overlapping faces mixed with N-gons for starters. Probably what happens when you build edges across a face with F instead of J, and some other odd stuff Blender will let you do.

Looks a bit like a mess though, so there’s more than that which needs fixing.

I believe my problem is not exacly the same, but it is described by the title of this topic (and I can not create another one).

Normals are fine. Mesh is triangulated. Surface is flat.
(these are the most common answers to that problem, but not in my case)
You can see it at the screenshot below:



Piture: object mode (top), edit mode (bottom)

Remove Doulbles gives no Vertices, I can not see any faces overlaping.
You can see that the inner (smaller) cylinders have less faces, and the outer cylinder (larger) has twice as much (I did subdivide it). I can assume it is relaed to that subdivision. I have made subdivision (selecter upper and lower edge of cylinder and pressed W - Subdivision), then selected new edges and scaled them on X and Y axis on 1.05 (or on some similar multiplier).

What can this problem be caused by?

P.S. Disabling Auto Smooth (Object - Normals - Auto Smooth) helps.