On my paint I noticed I applied much thinner coats to the roof - not intentionally. Thats just the way it turned out. Part of it is the angle your viewing it at makes it look thicker, and part of it is that its much harder to make it look smooth, so you tend to roll over and over again till it looks smooth, which makes it thinner.

When I figured that out, I started checking other spots out at angles around 60-70 degrees.

That really helped on the sides where it looked good straight on, but sitting in my shop looking out at the car at almost a 90 degree angle, I could see every little flaw where it was too thin or orange peeled