| 00 | Derment / Baron / Puddester / Bernheim | Team Vision (USA) | Steve Bernheim | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 01 | Pruett / Papis / Dixon / Morales | CGR Grand Am (USA) | Chip Ganassi | Riley | Mk XI | | Lexus | DP |
| 09 | Goad / Gordon / Duno / Grégoire | Spirit of Daytona Racing (USA) | Troy Flis | Crawford | DP03 | | Pontiac | DP |
| 2 | Wallace / Earnhardt, Jr. / Stewart | Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Chevrolet | DP |
| 4 | Leitzinger / Forbes-Robinson / Johnson / Brule | Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Chevrolet | DP |
| 5 | Maxwell / Pruskowski / Pruskowski / Bentley | Essex Racing (USA) | Mike Gue | Multimatic | MDP1 | | Ford | DP |
| 6 | Collins / Erdos / Wagner / Newton | Michael Shank Racing (USA) | Michael Shank | Doran | JE4 | | Lexus | DP |
| 7 | Lewis / Robinson / Baldwin / Rice / Southard | Southard Motorsports (USA) | Steve Southard | Fabcar | FDSC/03 | | BMW | DP |
| 9 | Borkowski / Mears, Jr. / Luyendyk, Jr. / Ham / Bell | Mears Motorcoach/SpeedSource (USA) | Sylvain Tremblay | Multimatic | MDP1 | | Ford | DP |
| 10 | Angelelli / Taylor / Collard | SunTrust Racing (USA) | Wayne Taylor | Riley | Mk XI | | Pontiac | DP |
| 11 | Alexander / Alessi / *Gay / *Mediani / *Dana | JMB Racing USA (USA) | Jean-Michel Bouresche | Ferrari | 360 Modena | N-GT | Ferrari | GT |
| 13 | Davis / Cawley / Espenlaub / Foster | Foxhill Racing (USA) | Michael Cawley | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 14 | Friedman / Wilson / Patch / Merzon / Smith | Autometrics Motorsports (USA) | Cory Friedman | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 15 | Gaylord / Kitch / Olsen / Hessert, III / *Hessert | Essex Racing (USA) | Mike Gue | Multimatic | MDP1 | | Ford | DP |
| 16 | Stanton / Murry / Sugden | AASCO Motorsports (USA) | Dennis Aase | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 17 | Kunz / Clark / Becker / Flanagan / *Webber | AASCO Motorsports (USA) | Dennis Aase | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 21 | Auberlen / Jönsson / Hand / *Said / *Marks | Prototype Technology Group (USA) | Tom Milner | BMW | M3 | E46 | BMW | GT |
| 22 | Jönsson / Said / Hand / Marks / Auberlen | Prototype Technology Group (USA) | Tom Milner | BMW | M3 | E46 | BMW | GT |
| 24 | Bambard / Halsmer / Heinricy / Nowicki | Specter Werks/Sports (USA) | Jack Cauley | Chevrolet | Corvette C5 | | Chevrolet | GT |
| 27 | Theys / Goossens / Lammers / Lienhard | Doran Lista Racing (USA) | Kevin Doran | Doran | JE4 | | Lexus | DP |
| 30 | Lazzaro / Kelleners / Bobbi | Risi Competizione (USA) | Giuseppe Risi | Maserati | Trofeo Light | | Maserati | GT |
| 33 | de Simone / Earle / Assentato / Longhi | Scuderia Ferrari of Washington (USA) | Allie Ash, Jr. | Maserati | Trofeo Light | | Maserati | GT |
| 37 | Littlechild / Pobst / Lally / Adam / Levitas | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 38 | Pobst / Lally / Littlechild / Bunting / Levitas | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 41 | Nonnamaker / Nonnamaker / Menard / Menard / Nonnamaker | Orison-Planet Earth Motorsports (USA) | Joe Nonnamaker | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 42 | Nonnamaker / Menard / Menard | TheRaceSite.com Racing (USA) | Joe Nonnmaker | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 44 | Fitzgerald / Liddell / Mowlem / Policastro / Policastro, Jr. | Orbit Racing (USA) | Rodger Hawley | Porsche | 996 GT3-RS | | Porsche | GT |
| 45 | Jeannette / Brockman / Newman / Petty | Gunnar Racing (USA) | Kevin Jeannette | Fabcar | FDSC/03 | | Porsche | DP |
| 46 | Argetsinger / Patterson / Pew / Victor / Cioti | Michael Baughman Racing (USA) | Michael Baughman | Chevrolet | Corvette | Z06 | Chevrolet | SGS |
| 47 | Baughman / Ward / Jaeger / Del Vecchio | Michael Baughman Racing (USA) | Michael Baughman | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 54 | Pilgrim / Borcheller / Fittipaldi / Barber | Bell Motorsports (USA) | James Bell | Doran | JE4 | | Pontiac | DP |
| 56 | Burgess / Collin / van Merksteijn / Rosa / Rosa | Seikel Motor Sport (D) | Peter Seikel | Porsche | 996 GT3-RS | | Porsche | GT |
| 57 | Vance / Masarati / Stevenson / Buttermore | Stevenson Motorsports/Auto Assets (USA) | John Stevenson | 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 / Riggins | Brumos Racing (USA) | Bob Snodgrass | Fabcar | FDSC/03 | | Porsche | DP |
| 60 | Puleo / Dubler / Kennedy / Evans | Xtreme Racing Group (USA) | Anthony Puleo | Chevrolet | Corvette | | Chevrolet | GT |
| 63 | Plumb / Lewis / Wolfkill / Escalette | Glenn Yee Motorsports (USA) | Glenn Yee | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 66 | Buckler / Bernhard / Long / Bergmeister | The Racers Group/Monster Cable (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 67 | Nearn / Ehret / Matthews / Nielsen / Sauvage | The Racers Group/Monster Cable (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 68 | James / Gleason / Valentine / Kroczek / Zimroth | The Racers Group/Monster Cable (USA) | Kevin Buckler | Porsche | 996 GT3-RS | | Porsche | GT |
| 70 | Tremblay / Wellman / Hall / Huang | SpeedSource (USA) | Sylvain Tremblay | Multimatic | MDP1 | | Ford | DP |
| 71 | Lacey / Wilkins / Nastasi / Wilkins / Wilden | Doncaster Racing (CDN) | John Lacey | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 72 | Lewis / McGlynn / Matos / Lluch | Jack Lewis Enterprises (USA) | Jack Lewis | Porsche | 996 GT3 Cup | | Porsche | GT |
| 73 | Peter / Montermini / Engelhorn / Quester | Red Bull BE Racing (A) | Baron/Engelhorn | Ferrari | 360 Modena | N-GT | Ferrari | GT |
| 74 | Pechnik / Neiman / Van Overbeek / Cunningham / Rockenfeller | Flying Lizard Motorsports (USA) | Johannes van Overbeek | Porsche | 996 GT3 Cup | | Porsche | GT |
| 75 | Neiman / Pechnik / Van Overbeek / Cunningham / Rockenfeller | Flying Lizard Motorsports (USA) | Seth Neiman | Porsche | 996 GT3-RS | | Porsche | GT |
| 80 | Guenette / Workman / Marshall / Marshall / *Spatafora | G&W Motorsports (USA) | Cole Scrogham | Picchio | DP2 | | BMW | DP |
| 82 | Lynn / Henricks / Brillhart / Heath | dds Racing (USA) | Steve Lynn | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 83 | Wilson / Mountain / Konig | Cirtek Motorsport (GB) | Robert Schirle | Porsche | 996 GT3-RS | | Porsche | GT |
| 86 | Krohn / Forristall / Van Wijk / Van Der Dys / Trentini | G&W Motorsports (USA) | Cole Scrogham | Porsche | 996 GT3 Cup | I | Porsche | SGS |
| 88 | Couceiro / Amaral / Gião / *Barbot | ASM Team (P) | Antonio Simoes | Porsche | 996 GT3-RS | | Porsche | GT |
| 91 | Dumoulin / Lieb / Julien / Pootmans | Doncaster Racing (CDN) | John Lacey | Porsche | 996 GT3 Cup | | Porsche | SGS |
| 93 | Drudi / Monfardini / Meneghello / Colasacco / Fonferko | Mastercar (I) | Mario Crugnola | Ferrari | 360 Modena | Challenge | Ferrari | GT |
| 94 | Casadei / Labhardt / Jurasz / Michaelian | Mastercar (I) | Mario Crugnola | Ferrari | 360 Modena | N-GT | Ferrari | GT |
| 97 | Orcutt / Thiel / Dobson / Jenkins | Graham Nash Motorsport (GB) | Graham Nash | Porsche | 996 GT3-R | | Porsche | GT |
| 98 | Zitza / Riddell / Von Seelen / de Quesada / Feinstein | GT Technologies (USA) | Marc Feinstein | Porsche | 996 GT3 Cup | | Porsche | GT |