MARIO KART: DOUBLE DASH UNLOCKABLES
All Cup Tour
By winning the Special Cup in the 150cc class to unlock the All Cup Tour, which is a combination of all of the four default cups.
Special Cup
By winning the Star Cup in the 100cc class.
Mirror mode
By winning the All Cup Tour in the 150cc class.
Luigi's Mansion battle arena
By winning the Mushroom Cup in the 150cc class.
Tilt-A-Kart battle arena
By winning the Flower Cup in mirror mode.
The Baby Park Ghost
If you have played time trials before, you should know this; On time trial mode, pick your driver and move to Baby Park to race on that stage. When you race make sure you do a dash head start. If you finish the time trial race in under 1:14, you can retry the race and face the staff ghost of Baby Mario and Luigi on the Mario Buggy. REMEMBER: they take the turns really sharply and do a Blue Boost.
Baby Luigi's Kart
By winning the Mushroom Cup in the 100cc class.
Birdo's Kart
By winning the Flower Cup in the 150cc class.
Bowser Jr.'s Kart
By winning the Special Cup in the 50cc class.
Daisy's Kart
By winning the Flower Cup in the 50cc class.