How do you get special cup on Mario kart double dash?

First, to unlock Mirror, get gold trophies (or just trophies, I'm not sure) in each Cup in 150CC. Mirror will then unlock. Then, play Mushroom and Flower Cup until you get a trophy. Star Cup will unlock. Play that until you get a trophy. Special will unlock. Hope this helps ^^ post here again if you need more help with this or anything else, I'll watch.