For 2008 Riley-Matthews Motorsports and GAINSCO/Bob Stallings Racing ran the #91 Riley MkXI-Pontiac 5.0L V8 without sponsorship. At the season-opening Rolex 24 at Daytona Hunter-Reay co-drove with Jim Matthews, Johnny O'Connell and Marc Goossens in the DP class. The car started in 3rd place both overall and in its class. The car completed 676 laps to finish in 8th place both overall and in its class. Hunter-Reay returned to the car for the season-ending SunRichGourmet.com 1000 at Miller Motorsports Park as a co-driver to Matthews and Goossens. The car started in 13th place both overall and in its class. The car would finish in 7th place both overall and in its class. Hunter-Reay finished 34th in the DP drivers standings with 47 points. The #91 Riley-Matthews Motorsports and GAINSCO/Bob Stallings Racing entry finished 10th in the DP teams championship with 303 points.