the COMPUTER wont let me answer you directly so im doing it this way.this game is about jimmie johnson and his friends as a teenager.supposedly,they were a bunch of grease monkeys and were fiercely competitive.they coined the phrase"i can outrace you on anything with wheels".this initialy got them into go-karts,bicycles,cars,trucks etc.then they got creative and took it to a new level.which was,literaly,rigging engines to anything they could think of.supposedly,all of the things you can race on this game were things they actualy used.
when i say supposedly it is because its hard to believe.
and for the other guy who posted.you beat this game by first going into career mode and averaging best by the 6th race.you can go back and pick and choose if you dont want to rerace the whole thing.
once you have done that,you get to take on jimmie johnson one on one.there are 8 cups so far that i have opened up.i have beaten 5 of them.i have not seen any credits yet.if there is no official way to beat it,make up your own.
by official i mean get to the last boss,beat him,watch end cut scene,view credits.
i am an albert einstien in a world filled with beavus and buttheads