2005 Preston raced in the AMA 250cc Supercross series, earning seven, top-10 finishes... Raced in the AMA 250cc Motocross Championship, earning overall top-five finishes at Sacramento, Calif., and Millville, Minn... Raced with American Honda team.

2004 Preston contested the AMA 125cc West Region Supercross series, earning five podium finishes... Preston raced a limited AMA 250cc Supercross season, best result was fourth-place at Minneapolis... Raced with Amsoil Honda team.

2003 Preston raced the AMA 125cc West Region Supercross series, taking a win at the Anaheim, Calif. season opener and earning four additional podium finishes... Preston raced select AMA 250cc Supercross races, best result was fourth-place at Daytona Beach, Fla... Raced with Amsoil Honda team.