Co-op Mode is a mode only in Mario Kart: Double Dash!!. It is when 2 players team up to race on Grand Prix. The 1st player drives, while the 2nd player throws items back and in front. Press 'Z' simutaneously to switch from driving and throwing. No more than 2 players can play in Co-Op Grand Prix. Other than having two human players in your kart, the mode is the same as regular GP. The Double Dash!! is a special ability that only works in Co-Op Mode where both team members press the A button when the signal light turns green. The thrower can also press L or R to hit another team of racers.