| 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 / Alfonso / Castillo | Grease Monkey Racing (USA) | Gene Sigal | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 09 | Goad / Grégoire | Spirit of Daytona Racing (USA) | Troy Flis | Crawford | DP03 | | Pontiac | DP |
| 2 | Duno / Wallace / Lammers | CITGO - Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Pontiac | DP |
| 3 | Grala / Lloyd | Cegwa Sport (USA) | Darius Grala | Fabcar | FDSC/03 | | Lexus | DP |
| 4 | Leitzinger / Forbes-Robinson / Edwards | Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Pontiac | DP |
| 5 | Pruskowski / Bentley / *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 | Southard Motorsports (USA) | Steve Southard | Fabcar | FDSC/03 | | BMW | DP |
| 9 | Borkowski / Mears, Jr. / Tremblay | Mears Motorcoach/SpeedSource (USA) | Sylvain Tremblay | Riley | Mk XI | | Pontiac | DP |
| 10 | Angelelli / Taylor | SunTrust Racing (USA) | Wayne Taylor | Riley | Mk XI | | Pontiac | DP |
| 11 | Orts / Michaelian / Gay | JMB Racing USA (USA) | Jean-Michel Bouresche | Ferrari | 360 Modena | N-GT | Ferrari | GT |
| 16 | Murry / *Stanton / *Webber | 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 | Hand / Marks / *Jönsson | Prototype Technology Group (USA) | Tom Milner | BMW | M3 | E46 | BMW | GT |
| 24 | Bambard / *Nowicki | Specter Werks/Sports (USA) | Jack Cauley | Chevrolet | Corvette C5 | | Chevrolet | GT |
| 27 | Magnussen / Theys / *Lienhard | Doran Lista Racing (USA) | Kevin Doran | Doran | JE4 | | Lexus | DP |
| 30 | Lazzaro / Kelleners / *Bennett | Risi Competizione (USA) | Giuseppe Risi | Ferrari | 360 Modena | GT | Ferrari | GT |
| 33 | Barbosa / Assentato / Earle | Scuderia Ferrari of Washington (USA) | Allie Ash, Jr. | Maserati | Trofeo Light | | Maserati | GT |
| 34 | Segal / *Buchwald / *Kenton | Scuderia Ferrari of Washington (USA) | Allie Ash, Jr. | Ferrari | 360 Modena | GT | Ferrari | GT |
| 36 | Pobst / Levitas / *Rockenfeller | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 37 | Pumpelly / Adam / Littlechild | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 38 | Lally / Bunting | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 39 | Hall / Huang / Davis | 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 | Shanaman / Shanaman / Nonnamaker | Orison-Planet Earth Motorsports (USA) | Joe Nonnmaker | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 43 | Shelton, Jr. / Shelton / Shelton | Orison-Planet Earth Motorsports (USA) | Joe Nonnamaker | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 44 | Fitzgerald / Policastro, Jr. / Policastro | Orbit Racing (USA) | Rodger Hawley | Porsche | 996 GT3-RS | | Porsche | GT |
| 46 | Longhi / Patterson / Pew | Michael Baughman Racing (USA) | Michael Baughman | Chevrolet | Corvette | Z06 | Chevrolet | SGS |
| 47 | Ward / Baughman / *Yeakle | Michael Baughman Racing (USA) | Michael Baughman | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 54 | Barber / Pilgrim / Borcheller | Kodak - Bell Motorsports (USA) | James Bell | Doran | JE4 | | Pontiac | DP |
| 57 | Vance / Lewis / Stevenson | Stevenson Motorsports/Auto Assets (USA) | John Stevenson | Porsche | 996 GT3-R | | Porsche | GT |
| 58 | Law / Maassen / Donohue | Red Bull - Brumos - Goodyear - Kendall (USA) | Bob Snodgrass | Fabcar | FDSC/03 | | Porsche | DP |
| 59 | France / Haywood / Luhr | Brumos - Goodyear - Kendall (USA) | Bob Snodgrass | Fabcar | FDSC/03 | | Porsche | DP |
| 65 | Master / Choulochas / *Schroeder | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 66 | James / Gleason / Valentine | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 67 | Halliday / Buckler / Kroczek | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 71 | Lacey / Wilkins / Dumoulin | Doncaster Racing (CDN) | John Lacey | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 72 | Matos / *Lewis | Jack Lewis Enterprises (USA) | Jack Lewis | Porsche | 996 GT3 Cup | | Porsche | GT |
| 73 | Baldwin / Tafel | Baldwin-Tafel Racing (USA) | Jack Baldwin/Jim Tafel | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 81 | Wagner / Martini / Collins | Rx.com/G&W Motorsports (USA) | Cole Scrogham | Doran | JE4 | | BMW | DP |
| 86 | McDowell / Van Wijk / Nastasi | G&W Motorsports (USA) | Cole Scrogham | Porsche | 996 GT3 Cup | I | Porsche | SGS |
| 92 | Cosmo / Gilbet / Stewart | Apple Motorsports (USA) | Gary Stewart | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 99 | Nearn / Schumacher | Schumacher Racing (USA) | Larry Schumacher | Porsche | 996 GT3-RS | | Porsche | GT |