I think my favorite vehicles go:
1. Hawk/Mech- Preferablly the mech, I try to use the Hawk but I'm really not the best.
4. Tank- I wanto to use it more, but I always get blownup
I've actually gotten some pretty high kills with the rb, though it varies from match to match. In my experience it is best suited for roadkilling, as it's about as fast as the sidewinder but it is four times as wide.
My favorite strategy is to turn on fieldmechanic and drive straight through the enemy base roadkilling people, drive away and let fieldmechanic kick in, then spin around and do it again. Good times!
There was this one time I was in the RB on one of thr cypress maps. some noob made a outpost outside my teams base. I ran him over. Then he respawned. So I ran him over again. I had the repair tool with me, so I would get out and repair it. Then I would get back in the RB and run him over some more. he didn't give up, and kept respawning.
I got 20 kills out of him.
Was that me? HAHA
I am persistent like that.