Here’s a model I made in a day (except for the machine gun and tires). Tell me what you think about the composite job, and please rate! 
The textures are done in Gimp and the DUDE is my best friend…I did an animation, but I have dialup, so it isn’t on youtube ;).
Cool.
Shadows look a bit odd though. 
Other than that very realistic. 
Cool! I like it.
As for crits, the tires look a bit flat, like they are embedded into to ground. And is that a tarp covering it? If so, it has a large area facing you that is too flat. A big stucci texture may fix it, or tweak the mapping of textures that are already on it. ( If that’s just a camouflage cover, that may be how you want it to look anyhow…)