Looking pretty good. Biggest thing I see are the tracks. They are way too rusty, especially for the desert. TRacks become very polished and have very little, to no rust in the desert. Here is an example from TankHeaven
More pics
here.Roadwheels need some dust to blnd them in better too.
Rear lights look off too. Only the left upper oval should be red. The lower left side shuold have one black slit. The right sid eshould have two black slits, a shorter one in the upper portion, and a longer wone in the lower portion. Like this:
Good job, a few tweaks and it can be great.