Two things affecting Fair-Play (IFV / Attack Heli)

1.) Squadmates can't repair the IFV  without losing the Secondary seat to someone who spawns on it, while you are repairing it.  This leaves the squadmate unable to gun and turns him into a full time passenger/repair monkey.

2.) Players constantly sit on the attack chopper's spawn location. Even if you or a squadmate gets the attack chopper from the spawn menu, the deployment camper will get the secondary seat every time.