Matt Hoffman's Pro BMX 2 Cheats

Play one player free ride and go to the London level. ride around the
outside of the level until you see another rider. try and run into him
and you get a new character.

In OK City, go up to the ramp that you put in place with the fork-lift and into the secret garage. Grind on the black box, and it will open up into a vert ramp. Use the ramp to grind onto the bullhorns, and jump into the small room to unlock Day Smith.

Go to OK city. Now go to the ramp that is put there with the fork lift and into the secret garage. Now you must grind on that black box and it will open into a vert ramp. Use that ramp and grind on the bullhorns and jump into the small room and you unlock Smith!