| 01 | Papis / Pruett | CompUSA Chip Ganassi with Felix Sabates (USA) | Chip Ganassi | Riley | Mk XI | | Lexus | DP |
| 02 | Diaz / Morales | CompUSA Chip Ganassi with Felix Sabates (USA) | Chip Ganassi | Riley | Mk XI | | Lexus | DP |
| 04 | Sigal / Puddester | Grease Monkey Racing (USA) | Gene Sigal | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 06 | Hemmingson / Lisa | ICY/SL Motorsports (USA) | Steve Lisa | Chevrolet | Corvette | | Chevrolet | GT |
| 09 | Grégoire / Goad | Spirit of Daytona Racing (USA) | Troy Flis | Crawford | DP03 | | Pontiac | DP |
| 2 | Duno / Wallace | CITGO - Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Pontiac | DP |
| 3 | Lloyd / Grala | Cegwa Sport (USA) | Darius Grala | Fabcar | FDSC/03 | | Lexus | DP |
| 4 | Forbes-Robinson / Leitzinger | Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Pontiac | DP |
| 5 | Pruskowski / Pruskowski | Essex Racing (USA) | Mike Gue | Multimatic | MDP1 | | Ford | DP |
| 6 | Negri / Frisselle | Michael Shank Racing (USA) | Michael Shank | Doran | JE4 | | Lexus | DP |
| 7 | Lewis / Rice | Southard Motorsports (USA) | Steve Southard | Fabcar | FDSC/03 | | BMW | DP |
| 9 | Mears, Jr. / Borkowski | Mears Motorcoach/SpeedSource (USA) | Sylvain Tremblay | Multimatic | MDP1 | | Ford | DP |
| 10 | Taylor / Angelelli | SunTrust Racing (USA) | Wayne Taylor | Riley | Mk XI | | Pontiac | DP |
| 16 | Stanton / Murry | AASCO Motorsports (USA) | Dennis Aase | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 21 | Auberlen / Said | Prototype Technology Group (USA) | Tom Milner | BMW | M3 | E46 | BMW | GT |
| 22 | Marks / Hand | Prototype Technology Group (USA) | Tom Milner | BMW | M3 | E46 | BMW | GT |
| 27 | Lienhard / Theys | Doran Lista Racing (USA) | Kevin Doran | Doran | JE4 | | Lexus | DP |
| 33 | Barbosa / Assentato / Earle | Scuderia Ferrari of Washington (USA) | Allie Ash, Jr. | Maserati | Trofeo Light | | Maserati | GT |
| 35 | Kennedy / Jermoluk | Scuderia Ferrari of Washington (USA) | Allie Ash, Jr. | Ferrari | 360 Modena | Challenge | Ferrari | SGS |
| 36 | Levitas / Pobst | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 37 | Adam / Littlechild | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 38 | Bunting / Lally | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 39 | Hall / Huang | Silverstone Racing Services (USA) | Larry Huang/Chris Hall | Crawford | DP03 | | Pontiac | DP |
| 41 | Nonnamaker / Nonnamaker | Orison-Planet Earth Motorsports (USA) | Joe Nonnamaker | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 42 | Van Wijk / Nonnamaker | Orison-Planet Earth Motorsports (USA) | Joe Nonnmaker | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 44 | Policastro, Jr. / Policastro / Fitzgerald | Orbit Racing (USA) | Rodger Hawley | Porsche | 996 GT3-RS | | Porsche | GT |
| 45 | Jeannette / Petty | Gunnar Racing (USA) | Kevin Jeannette | Porsche | 996 GT3-RS | | Porsche | GT |
| 46 | St. Amour / Yeakle | Michael Baughman Racing (USA) | Michael Baughman | Chevrolet | Corvette | Z06 | Chevrolet | SGS |
| 47 | Ward / Baughman | Michael Baughman Racing (USA) | Michael Baughman | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 54 | Barber / Borcheller | Kodak - Bell Motorsports (USA) | James Bell | Doran | JE4 | | Pontiac | DP |
| 57 | Vance / Stevenson | Stevenson Motorsports/Auto Assets (USA) | John Stevenson | Porsche | 996 GT3-R | | Porsche | GT |
| 58 | Law / Donohue | Red Bull - Brumos - Goodyear - Kendall (USA) | Bob Snodgrass | Fabcar | FDSC/03 | | Porsche | DP |
| 59 | France / Haywood | Brumos - Goodyear - Kendall (USA) | Bob Snodgrass | Fabcar | FDSC/03 | | Porsche | DP |
| 62 | Halsmer / Schmitt | Honda of America Racing Team (USA) | Kyle David Koestner | Acura | NSX | | Acura | GT |
| 66 | Valentine / James / Gleason | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 67 | Buckler / Halliday | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 70 | Wellman / Tremblay | SpeedSource (USA) | Sylvain Tremblay | Multimatic | MDP1 | | Ford | DP |
| 71 | Wilkins / Lacey | Doncaster Racing (CDN) | John Lacey | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 80 | Hugo Guenette | G&W Motorsports (USA) | Cole Scrogham | Picchio | DP2 | | BMW | DP |
| 81 | Wagner / Collins | Rx.com/G&W Motorsports (USA) | Cole Scrogham | Doran | JE4 | | BMW | DP |
| 91 | Julien / Dumoulin | Doncaster Racing (CDN) | John Lacey | Porsche | 996 GT3 Cup | | Porsche | SGS |