For using vehicles or destroying them this is my favorite loadout.
Description: vehicle
--
Primary: dmr or light rifle
Secondary: plasma pistol
Nades: plasma
AA: jet pack
Tactical: wheelman
Support: gunner
Description: the dmr or light rifle lets u weaken the vehicle from the safety of long range. Obviously though u can almost never destroy it with just that. Plasma pistols are obviously perfect to fight vehicles and the jet pack makes it a little easier to get close to vehicles while avoiding their fire especially from rocket weapons i.e. mantis, tank, rockethog. Once you've frozen the vehicle stick it with plasma nades or hijack it. Wheelman obviously is ideal for using vehicles whether as driver, gunner, or passenger it's great. Gunner is a nice perk not only for using vehicle chain guns but also greatly increasing ur movement speed using the machine gun turret which is quite effective against any vehicle, especially when u can move and jump at normal speed. Also, it's just plain fun being able to carry that beastly turret around quickly and mowing down enemies left and right. And when u use a speed boost with gunner u can carry around and fire the turret at normal sprint speed which makes u pretty lethal