| 00 | Bernheim / Derment / Puddester / Baron | Team Vision | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 01 | Pruett / Papis | CGR Grand Am | | Riley | Mk XI | | Lexus | DP |
| 09 | Goad / Wallace / Morgan / Conway | Spirit of Daytona Racing | | Crawford | DP03 | | Chevrolet | DP |
| 2 | Wallace / Earnhardt, Jr. / Stewart | Howard - Boss Motorsports | Rick Howard | Crawford | DP03 | | Chevrolet | DP |
| 3 | Grala / Lloyd | Cegwa Sport (USA) | | Fabcar | FDSC/03 | | Lexus | DP |
| 4 | Leitzinger / Forbes-Robinson / Brule / Johnson / Wallace | Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Chevrolet | DP |
| 5 | Pruskowski / Pruskowski / Bentley / Maxwell | Essex Racing | | Multimatic | MDP1 | | Ford | DP |
| 6 | Martini / Wagner / Newton / Erdos / Collins | Michael Shank Racing | | Doran | JE4 | | Lexus | DP |
| 7 | Lewis / Baldwin / Robinson / Southard | Southard Motorsports (USA) | Steve Southard | Fabcar | FDSC/03 | | BMW | DP |
| 9 | Mears, Jr. / Borkowski / Luyendyk, Jr. / Ham | Mears Motor Coach (USA) | Sylvain Tremblay | Multimatic | MDP1 | | Ford | DP |
| 10 | Taylor / Collard / Angelelli | SunTrust Racing (USA) | Wayne Taylor | Riley | Mk XI | | Pontiac | DP |
| 11 | Alexander / Gay / Alessi | JMB Racing USA | | Ferrari | 360 Modena | N-GT | Ferrari | GT |
| 13 | Cawley / Davis / Gibbs | Foxhill Racing | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 14 | Friedman / Patch | Autometrics Motorsports | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 15 | Kitch / Gaylord / Hessert / Hessert, III | Essex Racing | | Multimatic | MDP1 | | Ford | DP |
| 16 | Stanton / Murry | AASCO Motorsports | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 17 | Webber / Kunz | AASCO Motorsports | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 21 | Auberlen / Said / Marks / Hand / Halliday | Prototype Technology Group | | BMW | M3 | E46 | BMW | GT |
| 22 | Riggins / Negri | Heritage Motorsports (USA) | | Fabcar | FDSC/03 | | Lexus | DP |
| 24 | Heinricy / Nowicki / Bambard / Berry | Specter Werks / Sports | | Chevrolet | Corvette C5 | | Chevrolet | GT |
| 27 | Theys / Lienhard | Doran Lista Racing (USA) | | Doran | JE4 | | Lexus | DP |
| 30 | Anthony Lazzaro | Risi Competizione | | Maserati | Trofeo Light | | Maserati | GT |
| 33 | Earle / Assentato / Longhi | Scuderia Ferrari of Washington | | Maserati | Trofeo Light | | Maserati | GT |
| 37 | Littlechild / Adam / Pobst / Lally / Levitas | TPC Racing | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 38 | Bunting / Lally / Pobst / Levitas / Adam | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 41 | Nonnamaker / Nonnamaker / Nonnamaker | Planet Earth Motorsports | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 42 | Nonnamaker / Nonnamaker / Nonnamaker | The Race Site.com Racing | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 44 | Policastro / Pontoriero / Liddell / Mowlem / Fitzgerald | Orbit Racing (USA) | | Porsche | 996 GT3-RS | | Porsche | GT |
| 46 | Argetsinger / Pew / Cioti / Patterson / Victor | Michael Baughman Racing (USA) | | Chevrolet | Corvette | Z06 | Chevrolet | SGS |
| 47 | Baughman / Ward / Jaeger | Michael Baughman Racing (USA) | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 54 | Barber / Pilgrim / Borcheller / Duno | Bell Motorsports (USA) | | Doran | JE4 | | Chevrolet | DP |
| 57 | Stevenson / Vance / White | Stevenson Motorsports/Auto Assets | | Porsche | 996 GT3-R | | Porsche | GT |
| 58 | Donohue / Law / Luhr / Maassen | Red Bull - Brumos Porsche (USA) | Bob Snodgrass | Fabcar | FDSC/03 | | Porsche | DP |
| 59 | France / Haywood / Sharp / Goodyear | Brumos Racing (USA) | | Fabcar | FDSC/03 | | Porsche | DP |
| 64 | Dave Master | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 65 | Choulochas / Schroeder / Goldberger | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 66 | Buckler / Bernhard / Long / Bergmeister | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 67 | Nielsen / Nearn / Burnstine / Matthews | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 68 | Valentine / Kroczek / Zimroth / Halliday | The Racers Group (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 70 | Wellman / Tremblay / Huang / Hall | SpeedSource (USA) | Sylvain Tremblay | Multimatic | MDP1 | | Ford | DP |
| 71 | Lacey / Wilkins | Doncaster Racing | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 73 | Engelhorn / Peter / Montermini / Quester | Red Bull BE Racing | | Ferrari | 360 Modena | N-GT | Ferrari | GT |
| 74 | Neiman / Pechnik / Van Overbeek / Cunningham | Flying Lizard Motorsports | | Porsche | 996 GT3 Cup | | Porsche | GT |
| 75 | Neiman / Pechnik / Van Overbeek / Cunningham | Flying Lizard Motorsports (USA) | Seth Neiman | Porsche | 996 GT3-RS | | Porsche | GT |
| 79 | Jeannette / Newman / Petty / Brockman | Gunnar Racing (USA) | | Fabcar | FDSC/03 | | Porsche | DP |
| 80 | Spatafora / Marshall / De Simone / Marshall / Guenette | G&W Motorsports (USA) | | Picchio | DP2 | | BMW | DP |
| 82 | Brillhart / Heath / Henricks / Lynn | dds Racing | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 83 | Mountain / Wilson | Cirtek Motorsport (GB) | | Porsche | 996 GT3-RS | | Porsche | GT |
| 86 | Van Wijk / Trentini / Van Der Dys / Guenette | G&W Motorsports (USA) | Cole Scrogham | Porsche | 996 GT3 Cup | I | Porsche | SGS |
| 87 | Gary Stewart | G&W Motorsports | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 88 | Couceiro / Amaral / Barbot | ASM Team | | Porsche | 996 GT3-RS | | Porsche | GT |
| 91 | Julien / Dumoulin | Doncaster Racing | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 96 | Becker / Flanagan / Clark | AASCO Motorsports | | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 98 | Feinstein / Riddell, Jr. / Zitza / Von Seelen | GT Technologies | | Porsche | 996 GT3 Cup | | Porsche | GT |
| 99 | Schumacher / Zacharias | Schumacher Racing | | Porsche | 996 GT3-RS | | Porsche | GT |
| 119 | Pootmans / Wilkins | Doncaster Racing | | Porsche | 996 GT3 Cup | I | Porsche | SGS |