Hey Bro
For years I have gone to a site called
Renderosity...
A site dedicated to the finished product of an artists work each program having it's own forum and it has one for 3d studio max...
I use maya but most of them are interchangable with each other...model wise...anyways go there and post your specific question in the Max forum there and the other bros there I'm sure will help you out.
It's free to join...maybe you already know about it but in case you dont.
Wow I see there is a guy in there who worked on a tank scene...you'll see it.
Tank Animation