I mentioned this a long time ago before even Red hammer came out I believe. AI should have a better IFF (identify friendly foe) system. As it is now, they will not fire on empty vehicles regardless if the enemy can use them or not. ( I know I would destroy a T80 if it worked and the crew was just outside of it) It also knows when 1 of its vehicles have been comandeered. If you steal a T72 and drive it into a soviet base, they won't know that you are a US soldier until you start killing them. Also, If you drove that same T72 to your base, some private with an AT4 will shoot at you because he thinks your a soviet, not like current ai.
this would probably be easy to implement because all youd really have to do would be to change the 'side' of a unit while it was in the vehicle