That is some really great brush work. I am a big believer in making a vehicle looking very used... that is if it lasts long enough in the field. One thing I noticed though and it is probably just the way the picture is taken. In your second pic on your original post, the one that shows the windshield, is the windshield painted as part of a camo scheme or just dirty? If it's just dirty then the contrast of clean to dirty is pretty dramatic. If it is that dirty I would think that the wipered part would be pretty streaky.
And I know you are going to hate this but once seen can't be unseen. Have you ever seen the Disney movie "Cars"? In this anamated movie the cars have eyes in the windshields. When I looked at the second pic the windshield looked like it has "eyes". Especially the driver side (left hand drive) with something of the background showing through, it looks like an eye.
The overall impression of your painting is very impressive though. Military vehicles during the war did not get great paint jobs from the factory and you have depicted the wear off of paint great! Great job!