The Ar.7 and Ar.8 are two widely used armored troop carriers. The Ar.7 is known as one of the best vehicular successes by Costigar It was produced in large numbers and exported all around the world. The Ar.8, while not as widely used, was a direct improvement over the Ar.7. The whole troop compartment was extended forward, giving troops more room in the back, and providing the driver the extra armor. It also featured a second main cannon mounted on the side, directly to the right of the driver.
About this creation
Both vehicles came in many different versions. Here you can see the Ar.7 mounted with a cannon.
Getting the inside lined up with the outside was a bit of a pain. I used two different hinges, and simply aligned the breach area to the barrel. In fact, the two aren't connected at all!
I really like the use of the double tread. It's a good width, and in theory, if one were broken (say in combat) the vehicle could continue to move (even if only for a limited time). I also like the way the color matches your SPA. Attack!