O'Quinn was chosen to pilot the Roush Racing No. 50 Ford Fusion for the full 2006 NASCAR Nationwide Series season after being chosen from four finalists from Discovery Channel's Roush Racing: Driver X competition.
O'Quinn brought a lengthy resume to Roush Racing. With experience in go-karts, Super Stocks, Late Models, the ARCA RE/MAX Series, a UARA National Championship and USAR Hooters Pro-Cup Series Southern Division Rookie of the Year honors, O'Quinn went without shortage of experience behind the wheel. That season, O'Quinn raced 33 of 35 events, gained one top-five, and five top-10s, giving him a 19th place finish in the Championship rankings.
In 2007, O'Quinn not only raced in the Nationwide Series finishing the season in 48th, but he also competed in the NASCAR Camping World Truck Series, gaining one top-10 finish.
In 2008, O'Quinn will race the Nationwide Series in the No. 56 Power Equipment Chevrolet for John McNelly.