Just a hint about the model - because it will be basically used from various top-view angles, it will work inside game bit better, if its sides aren't strictly vertical or narrower than top, but on opposite the top narrower than central-bottom area.
Otherwise it's nice piece

, in physic only the AI value on 0 doesn't seem to be greatest idea, the AIs then control it by very in a nervous fashion, loose time by it and are not very competitive.
