This is my first 3d model, I really want you opinions, on what to improve and I also want suggestions

The nice looking tank is the scorpion tank from Generals, I put it there so I could compare mine to it, then I took the screenshots when it was there, so that's why it is in the pics
I haven't exported this tank from gmax, and I'm not sure I will be able to do any textures, I don't think I want to export it anyway.. But please come with suggestions, comments and ideas!