You have to pass all the other champions and when you reach him, I think you should get a lot of the speeds(green block) and get 3 whites. Try to get as many as him and you might win Rocket Racer....
Beat all bosses!!!
To make that easy complete the vortex in every level.
Boss1: You need speed.
Boss2: You need shield.
Boss3: You need grip.
If you want more tips my e-mail is xalax@abv.bg