Teams have done it, but it's not as favorable. You don't get as much pushing power with 2 motors powering the bot, and you can't maneuver as fluidly as other drives. We used this in 2008, if memory serves correct, and it didn't work out so well.

Since you're a car guy, I'll put it like this. In a pushing match between 2 cars. both with the same weight, traction, and motors, who would win: A standard car, or a car with power to every wheel? Or a car with more wheels and power to them, for that matter.

Also, which is more maneuverable: A standard car, or a wheelchair?

Hope this helps!