I really like what you've done here. I think the straightness of the lines on the back of the truck are the bit which looks a bit off i.e. they look too pristine. Don't know if there's an easy way to make it a bit more "wobbly".
This one I quickly "wobbled" in photoshop. Not a great job, and far too blurry (pretty much a "smudge tool" up and down for a minute and a quick adjustment on the saturation), but it might illustrate a bit better what I mean.
Redoing similar with a little care and attention (like spending more than 2 minutes on it) might do the job, unless you're going for a really accurate "Fallout feel" where you'd need to painfully repaint the whole thing over the top of the model - a lot of the detail on the original ones has got a definite "drawn on" feel to it. I don't know how the original vehicles were done, but I think that's how a lot of the other additional vehicles have been done on NMA and so on.
Of course, it's all well and good photoshopping the still image, but it's be nice if you could "wobble up" the original model, so if it turns out that the angle is a few degrees off, you don't have to repaint it every time you make a minor adjustment.
