Getting a new Tank in-game

What does it take to get a new tank in-game ?
I can get one in the game but it has serious problems:

Once in-game it is not able to turn with the same turning ability as the default tank.

I took the m1a1_barrel.ms3d, m1a1_base.ms3d, ma1a_body.ms3d and m1a1_turret.ms3d from the source art and created new .dts files and they exhibit the same behavior.

-- CORRECTION: The source art does work. (in game.cs I was adding my new vehicle before the wheeledvehicle.cs (the parent). Make sure you add your vehicle script after the commented lines that say "//parent, must come before derived vehicles".
Back to adding my custom tank.........


Is the source art up-to-date ?

Still concerned with the source art:

Also - still seem to be missing some source art - the source for the tank wheels does not appear to be included. (What else is missing ?)

Thanks !