As Bob mentioned that we could use military vehicles, I will be modeling a M103 Heavy Tank.
Pic found at commons.wikimedia.com

CAT Project

Caterpillar Lexion 580R Combine

my CAT - Michelle Hodulik

My CAT vehicle is the Compact Wheel Loader 906H. I found information and a 3D virtual look at this model at http://www.cat.com/cda/layout?m=308866&x=7