Those couple of shots are OK for first draft models, but you need to learn to use less slightly-modified primatives, and craft more of the 3-d shapes yourself. Some of the pro's are ound here are better at explaining this than a noob like me.
The biggest reason you'll want to give those models one more pass before you try to start using them, is that they have a
TON of wasted faces, which besides causing load for spring with no graphical benefit, and most importantly, will multiply your work x10 or maybe even more when you try to texture them.
For starters, take the top of the vehicle (the deck) and join those several dozen faces into a single one. It's a flat square, you certanly don't need more than one face. Then, reduce the # of sides on the barrell, since Spring will smooth sides that are arrainged around a common point anyway. Check out
http://taspring.clan-sy.com/phpbb/viewt ... c&start=40 for help with this. I think 8 sides would be good, but Argh or Smoth would know for sure.
Along similar lines, the base of the turrets could probably use less as well.
Finally, the tracks REALLY need work, but for modifying them, you need to ask someone more experienced than me. I can think of a few ways to make them OK, but on of the better guys could probably tell you how to make them good.
Sorry for all the criticism, just trying to save you before you try to texture that stuff. Best of luck with the mod.