You don't have to win races to get points. Doing Flips Rolls and hellicopter spins also rack up the points. To rapidly gain points, go to the options screen and set the laps to 6. Then start a championship on easy.

There are many jumps in the first level. Before each jump, pump the gas twice to perform a flip. You can even flip off the back of opponent cars if in the right position. Press the gas+Left or Right on the analog to do a 2 wheel side wheelie. Perform this before a jump and you'll roll.

Do all 6 laps performing as many tricks as you can. When done, get the points and quit. Go back to options and set the laps to 1. Go back to championship and finish the next two easy tracks. Repeat process and you'll have many points in no time flat.

Go into the Options and set the number of Laps to 6, now start a Championship circuit, it doesn't matter which difficulty setting you use (I've found that Pro or Master works best). Select Germany as your track, now race around the track doing as many tricks as you can, Mega Roll's work best. Now if you come in 1st and do enough tricks you can get over 140 points (on Master). On the next track (Egypt) pause the game and select "End Championship", now you can start at Germany again and repeat the process. I hope this is clear and easy enough to understand.