Turkey2 no its not possible to edit vehicles in AH not for us anywayI
Only the HTC staff have that power and then it would be released as a patch, along with a news update on new vehicle etc.
The closest we'll get is with the new terrain editor which will enable us to create custom skins (paintwork) specific to the map that you make. (i think)
My tank is made in 3ds Max (trying to match lighting) and then photoshoped into a screenshot of AH
