People win races, not cars. Just look at Tebo, he kicked ass with AE, and now he's kicking ass with Kyosho.
I really believe that these guys are so good that it matter very little what they drive (within reason of course).
With that said, I would say Masami, Tebo, and Cavalieri all have a very good shot.
My bet is on either Tebo or Cavalieri. Either one could take 4wd or 2wd.