Ahh, you know I just did some handling like this for a jeep and it worked out pretty well. I used a limbed model, like the body was limb 1, then the wheels were limbs 2 to 5. I simply grabbed the ground height and limb height of all the wheels and used it to ascertain what the real wheel heights should be, then I rotate limb 1 to suit the angle of the landscape.
Because of the way DB handles it's rotations, you can't rotate an object on X and Y at the same time, to do what your trying to do, you'd have to glue your tank onto a hidden dummy object and then rotate the dummy object on Y, and the tank object on X - however rotating limb 1 means you don't have to worry about that.
If you can get 4 dummy limbs into the corners of the tracks I can give you a little example (like email me the .3DS and .X versions of your tank with the limbs setup and pivots set). Obviously it's more logical with a jeep because you simply use it's wheels with a drop off height to find the base, but with a tank you'd need dummy limbs.
Van-B
Van-B
The nature of Monkey was irrepressible!.
