The real purpose for a double clutch was to save your synchros, in a car, your in first, you push in the clutch shift to neutral, let the clutch out, push the clutch in again, shift to second, let go of the clutch. Thats double clutching, i can't see it being done in a 4 wheeler, maybe like shavo said, but thats not a true double clutch.

 

and if you tried that, once you got down too far in the gears the tires would lock up......

 

Thanks for the replys guys and girls if there was any.