I wouldn't call a G6 small--just try the G5 or Vibe! (Ah, the joys of working at a Pontiac dealer...)
At the same time, I've wondered just how small a vehicle one could fit an FRC robot into. My first-gen Honda CR-V
fits one 60"-tall robot on its side without bumpers, and it's no Hummer; can anyone vouch for fitting one into something smaller?