Yes, the STi is bunta, I know it only showed his mouth, and no it didn't have a cigarette in it, but still, it was bunta. Notice how after the racing shot they showed the tofu shop and it was empty?
Besides the only other AWD cars would be the GTR skyline (which he says is too heavy) the Evolution, which has already been beaten, and the scooby WRX STi Type R (2-door = type R).
It's either a v5 or v6 STi too, you can tell from the front bumper.
Now i just wish I knew what the hell they were saying. It's amazing how much of the story you can follow just by watching the animation, even though you dont understand the words.