shortcuts in Mushroom Bridge? I wasn't aware of any so I done my best time on travelling on the road.
EDIT:
Well, I also have tried Bowser's Castle and the best I could get was 58.6 seconds for one lap. (gl to everyone who wants to beat Plisco's record, you have to go a little past perfection). Anyway, does anyone know how to get the best boost? I try pressing the 'A' button repeatedly fast but sometimes that gives me a worse or good or better or no boost at all (comparing it with my ghost runner).