| 01 | Scott Pruett / Max Papis / Scott Dixon / Jimmy Morales | Riley Mk XI Lexus | CGR Grand Am |
| 09 | Doug Goad / Robby Gordon / Milka Duno / Stéphane Grégoire | Crawford DP03 Pontiac | Spirit of Daytona Racing |
| 2 | Andy Wallace / Dale Earnhardt, Jr. / Tony Stewart | Crawford DP03 Chevrolet | Howard - Boss Motorsports |
| 4 | Butch Leitzinger / Elliot Forbes-Robinson / Jimmie Johnson / David Brule | Crawford DP03 Chevrolet | Howard - Boss Motorsports |
| 5 | Scott Maxwell / Joe Pruskowski / Justin Pruskowski / Ross Bentley | Multimatic MDP1 Ford Focus | Essex Racing |
| 6 | Kelly Collins / Thomas Erdos / Cort Wagner / Mike Newton | Doran JE4 Lexus | Michael Shank Racing |
| 7 | Shane Lewis / George Robinson / Jack Baldwin / Vic Rice / Stephen Southard | Fabcar FDSC/03 BMW | Southard Motorsports |
| 9 | Mike Borkowski / Paul Mears, Jr. / Arie Luyendyk, Jr. / Nick Ham / Justin Bell | Multimatic MDP1 Ford Focus | Mears Motorcoach/SpeedSource |
| 10 | Max Angelelli / Wayne Taylor / Emmanuel Collard | Riley Mk XI Pontiac | SunTrust Racing |
| 15 | Dave Gaylord / Don Kitch / John Olsen / Tom Hessert, III / *Tom Hessert | Multimatic MDP1 Ford Focus | Essex Racing |
| 16 | Craig Stanton / David Murry / Tim Sugden | Porsche 996 GT3 Cup | AASCO Motorsports |
| 17 | Joe Kunz / Derek Clark / Gary Becker / Patrick Flanagan / *Mark Webber | Porsche 996 GT3 Cup | AASCO Motorsports |
| 21 | Bill Auberlen / Niclas Jönsson / Joey Hand / *Boris Said / *Justin Marks | BMW M3 E46 | Prototype Technology Group |
| 22 | Niclas Jönsson / Boris Said / Joey Hand / Justin Marks / Bill Auberlen | BMW M3 E46 | Prototype Technology Group |
| 24 | Tom Bambard / Pete Halsmer / John Heinricy / Jeff Nowicki | Chevrolet Corvette C5 | Specter Werks/Sports |
| 33 | Fabrizio de Simone / Stephen Earle / Emil Assentato / Nick Longhi | Maserati Trofeo Light | Scuderia Ferrari of Washington |
| 38 | Randy Pobst / Andy Lally / John Littlechild / Marc Bunting / Michael Levitas | Porsche 996 GT3 Cup | TPC Racing |
| 45 | Gunnar Jeannette / Mike Brockman / Paul Newman / Kyle Petty | Fabcar FDSC/03 Porsche | Gunnar Racing |
| 46 | Peter Argetsinger / Mark Patterson / John Pew / Jim Victor / Dario Cioti | Chevrolet Corvette Z06 | Michael Baughman Racing |
| 47 | Michael Baughman / Bob Ward / Brad Jaeger / Frank Del Vecchio | Porsche 996 GT3 Cup | Michael Baughman Racing |
| 54 | Andy Pilgrim / Terry Borcheller / Christian Fittipaldi / Forest Barber | Doran JE4 Pontiac | Bell Motorsports |
| 56 | Tony Burgess / Philip Collin / Peter van Merksteijn / Gabrio Rosa / Fabio Rosa | Porsche 996 GT3-RS | Seikel Motor Sport |
| 57 | Chip Vance / Piers Masarati / John Stevenson / John Buttermore | Porsche 996 GT3-R | Stevenson Motorsports/Auto Assets |
| 58 | David Donohue / Darren Law / Lucas Luhr / Sascha Maassen | Fabcar FDSC/03 Porsche | Red Bull - Brumos Porsche |
| 59 | J. C. France / Hurley Haywood / Scott Sharp / Tommy Riggins | Fabcar FDSC/03 Porsche | Brumos Racing |
| 63 | Hugh Plumb / Michael Lewis / Kim Wolfkill / Geoff Escalette | Porsche 996 GT3 Cup | Glenn Yee Motorsports |
| 70 | Sylvain Tremblay / Selby Wellman / Chris Hall / Larry Huang | Multimatic MDP1 Ford Focus | SpeedSource |
| 72 | Jack Lewis / Tom McGlynn / Manuel Matos / Edison Lluch | Porsche 996 GT3 Cup | Jack Lewis Enterprises |
| 74 | Lonnie Pechnik / Seth Neiman / Johannes Van Overbeek / Peter Cunningham / Mike Rockenfeller | Porsche 996 GT3 Cup | Flying Lizard Motorsports |
| 80 | Hugo Guenette / Jason Workman / Steve Marshall / Danny Marshall / *Fabio Spatafora | Picchio DP2 BMW | G&W Motorsports |
| 82 | Steven Lynn / Jack Henricks / Jim Brillhart / Terry Heath | Porsche 996 GT3 Cup | dds Racing |
| 83 | Rob Wilson / Frank Mountain / Martyn Konig | Porsche 996 GT3-RS | Cirtek Motorsport |
| 88 | Pedro Couceiro / Miguel Amaral / Manuel Gião / *Carlos Barbot | Porsche 996 GT3-RS | ASM Team |
| 93 | Luca Drudi / Ferdinando Monfardini / Matteo Meneghello / Joe Colasacco / Ross Fonferko | Ferrari 360 Modena Challenge | Mastercar |
| 94 | Mauro Casadei / François Labhardt / Manfred Jurasz / Jim Michaelian | Ferrari 360 Modena N-GT | Mastercar |
| 75 | Seth Neiman / Lonnie Pechnik / Johannes Van Overbeek / Peter Cunningham / Mike Rockenfeller | Porsche 996 GT3-RS | Flying Lizard Motorsports |
| 37 | John Littlechild / Randy Pobst / Andy Lally / Bill Adam / Michael Levitas | Porsche 996 GT3 Cup | TPC Racing |