I couldn't unlock the last race without getting all 14 achievements to unlock the boost all the time. Even with the F3 fully upgraded at 100%! After I went back I was able to, the only ones I had left were the 50 cones and the 10 ist place wins.
This game is awesome. At first I couldn't figure out that thats all you had to do was pull down more ships to buy them. Once I figured that out the game was more enjoyable. I really liked it.
 "Coaster Racer 3"){kind=icon}
 "Caribbean Admiral"){kind=icon}