• SuperPro Fritz Leesman
• SuperPro Jon Allen
• SuperPro Marc Elliott
• SuperPro Nick Halen
• SuperPro Lorenzo Mandarino
• Former SKI Driver of the Year and current TransAtlantic contender Alan Scuito
• PKC #1 Slava Prikhodko and the always dangerous Nick Brinkman
• Arizonan fast cats Arie Luyendyk, Jr. and Bud Grossenbacher

Mazda Motorsports has signed on to be the presenting sponsor of Superkarts! USA's So Cal region ProKart Challenge beginning this weekend, as the series takes over the CalSpeed Karting Center in Fontana CA for the fourth round of the ten race championship. Mazda joins PKC title sponsor Eagle One Racing / Hi-Tech Engines and a bevy of class sponsors in 2007 including, Mothers Polish, MG Tires, KLS Racing, Keller Williams Realty, American Home Mortgage, Blue Agave Southwestern Grill, Big O Tires, RLV, SSC Racing, HitchHiker Kart Stands, FX Racing/Trackmagic, Classy Auto Detailing, Russell Karting and Absolute Screenprint.

ProKart Challenge has just announced the following prizes for 2007 with more to follow in the coming months (including chassis, motors, tires and more). Must be present at awards banquet to win.