| 00 | Baird / Morris / Ambrose / Teulan | Aussie Assault (AUS) | John Teulan | Porsche | 996 GT3 Cup | | Porsche | GT |
| 01 | Pruett / Diaz / Briscoe | CompUSA Chip Ganassi with Felix Sabates (USA) | Chip Ganassi | Riley | Mk XI | | Lexus | DP |
| 02 | Johansson / Wagner / McMurray | New Century Mtg/Chip Ganassi w/Sabates (USA) | Chip Ganassi | Riley | Mk XI | | Lexus | DP |
| 03 | Dixon / Mears / Manning | Target Chip Ganassi with Felix Sabates (USA) | Chip Ganassi | Riley | Mk XI | | Lexus | DP |
| 04 | Sigal / Konôpka / Hanson / Konstant / Wilton | Sigalsport (USA) | Gene Sigal | Porsche | 996 GT3 Cup | | Porsche | GT |
| 05 | | Grease Monkey Racing (USA) | Gene Sigal | Porsche | 996 GT3 Cup | | Porsche | GT |
| 06 | Derment / Lewis / Hainer / Roush / Bernheim | Bernheim Porsche Racing (USA) | Steve Bernheim | Porsche | 996 GT3 Cup | | Porsche | GT |
| 08 | Goldin / Finlay / Goldin / Shuster | Goldin Brothers Racing (USA) | Steve Goldin | Mazda | RX-8 | | Mazda | GT |
| 09 | Goad / Grégoire / Moreno / Ward | Spirit of Daytona Racing (USA) | Troy Flis | Crawford | DP03 | | Pontiac | DP |
| 2 | Franchitti / Duno / Franchitti / Wheldon | CITGO - Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Pontiac | DP |
| 3 | Grala / Patterson / Wahl / Kroczek / Lewis | Cegwa Sport/Southard Motorsports (USA) | Darius Grala | Fabcar | FDSC/03 | | Lexus | DP |
| 4 | Leitzinger / Forbes-Robinson / Johnson | Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Pontiac | DP |
| 5 | Dyson / Brix / Dyson / Gue | Essex Racing (USA) | Mike Gue | Crawford | DP03 | | Ford | DP |
| 6 | Borkowski / Mears, Jr. / Connor / Dayton | Michael Shank Racing (USA) | Michael Shank | Riley | Mk XI | | Pontiac | DP |
| 8 | Frisselle / Erdos / Frisselle / Newton | Rx.com/Synergy Racing (USA) | Cole Scrogham | Doran | JE4 | | BMW | DP |
| 9 | Zacharias / Donner / Foster / Skelton / Rosser | Hyper Sport (USA) | Brad Nyberg | Doran | JE4 | | Infiniti | DP |
| 10 | Angelelli / Taylor / Collard | SunTrust Racing (USA) | Wayne Taylor | Riley | Mk XI | | Pontiac | DP |
| 11 | Plumb / Gooding / Boss / Michaelian | JMB Racing USA (USA) | Bouresche/Manfredi | Ferrari | 360 Modena | Challenge | Ferrari | GT |
| 14 | Keen / Friedman / Bacon / Johnson | Autometrics Motorsports (USA) | Cory Friedman | Porsche | 996 GT3 Cup | | Porsche | GT |
| 16 | Bentley / Braun / Carrio / Coleman / Buckler | TRG (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | GT |
| 18 | Miller / Bingham / Ivankovich / Burgess / *Rice | Chase Competition Eng/CB Motorsports (USA) | Robert Chase | Chase | CCE-001 | | Pontiac | DP |
| 19 | Gidley / McDowell / Valiante / Bomarito | Ten Motorsports (USA) | Rob Finlay | Riley | Mk XI | | BMW | DP |
| 20 | Wallace / Lammers / Stewart | CITGO - Howard - Boss Motorsports (USA) | Rick Howard | Crawford | DP03 | | Pontiac | DP |
| 21 | Auberlen / Hand / James / Gleason | Prototype Technology Group (USA) | Tom Milner | BMW | M3 | E46 | BMW | GT |
| 22 | Marks / Milner / Collins / Valentine | Prototype Technology Group (USA) | Tom Milner | BMW | M3 | E46 | BMW | GT |
| 23 | Espenlaub / Szekeres / Hanson / Villamil / Del Vecchio | Horizon Motorsports LLC (USA) | Jim Harrell | Pontiac | GTO | | Pontiac | GT |
| 29 | Vargo / Vargo / Vargo / Refenning | Brumos Racing (USA) | Bob Snodgrass | Fabcar | FDSC/03 | | Porsche | DP |
| 36 | Pobst / Pumpelly / Dumoulin / Levitas / Littlechild | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | GT |
| 37 | Fitzgerald / Matos / Assentato / *Longhi | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | GT |
| 39 | Goossens / Smith / Sharp / Matthews | Orbit Racing (USA) | Rodger Hawley | Riley | Mk XI | | Pontiac | DP |
| 41 | Nonnamaker / Nonnamaker / Nonnamaker / Jakes | Team Sahlen (USA) | Joe Nonnamaker | Porsche | 996 GT3 Cup | | Porsche | GT |
| 42 | Zitza / Nonnamaker / Nonnamaker / Jakes / Gonzalez, Jr. / Allen / Blum / Lux | Team Sahlen (USA) | Joe Nonnamaker | Porsche | 996 GT3 Cup | | Porsche | GT |
| 43 | Zitza / Blum / Lux / Allen / Gonzalez, Jr. | Team Sahlen (USA) | Joe Nonnamaker | Porsche | 996 GT3 Cup | I | Porsche | GT |
| 44 | Magnussen / Labonte / Labonte / Herta | Doran Racing (USA) | Kevin Doran | Doran | JE4 | | Pontiac | DP |
| 46 | Baughman / Yeakle | Michael Baughman Racing (USA) | Michael Baughman | Chevrolet | Corvette | | Chevrolet | GT |
| 48 | Seiler / Hauser / Puleo / Dubler | Xtreme Racing Group (USA) | Anthony Puleo | Chevrolet | Corvette | | Chevrolet | GT |
| 49 | Maxwell / Busch / Kenseth / Biffle | Multimatic Motorsports (USA) | Barry McSherry | Multimatic | MDP1 | | Ford | DP |
| 50 | Bucknum / Nastasi / Zogaib / Peterson / Duder | Blackforest Motorsports (USA) | Brian Nott | Multimatic | MDP1 | | Ford | DP |
| 51 | Wendlinger / Mowlem / Vosse / Quester | Red Bull Ebimotors (I) | Simone Petri | Porsche | 996 GT3 Cup | | Porsche | GT |
| 52 | Drudi / Rosa / Monzón / de Villota | Mastercar (I) | Mario Crugnola | Ferrari | 360 Modena | Challenge | Ferrari | GT |
| 53 | Ragazzi / Diez de Villarroel / Chiminelli / Bertuzzi | Mastercar (I) | Mario Crugnola | Ferrari | 360 Modena | Challenge | Ferrari | GT |
| 54 | Fittipaldi / Tracy / Borcheller / Kelleners / *Barber | Kodak - Bell Motorsports (USA) | James Bell | Doran | JE4 | | Pontiac | DP |
| 55 | Arnold / Thiel / Stevenson / MacAlpine / Turner | ASC Motorsports (USA) | Zach Arnold | Chevrolet | Corvette | | Chevrolet | GT |
| 58 | Donohue / Law / Luhr / Maassen | Red Bull/Brumos Racing (USA) | Bob Snodgrass | Fabcar | FDSC/03 | | Porsche | DP |
| 59 | France / Haywood / Bernhard / Rockenfeller / Dumas | Brumos Racing (USA) | Bob Snodgrass | Fabcar | FDSC/03 | | Porsche | DP |
| 61 | Nearn / Wilkins / Lacey / Shep / Wilkins | TRG East (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | GT |
| 62 | Inoue / Fujita / Wada / Hirakawa / Takahashi | Auto Gallery/TRG (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | GT |
| 63 | Master / Flanagan / Sluszny / Clark | Auto Gallery/TRG (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | GT |
| 64 | Couceiro / Policastro, Jr. / Sauvage / Amaral / Policastro | Auto Gallery/TRG (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | GT |
| 65 | Lally / Bunting / Plumb / de Quesada / Buckler | Auto Gallery/TRG (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | GT |
| 66 | Papis / Bergmeister / Gavin | Krohn Racing/TRG (USA) | Krohn/Buckler | Riley | Mk XI | | Pontiac | DP |
| 67 | Jönsson / Krohn / Rice / Said / Morales | Krohn Racing/TRG (USA) | Krohn/Buckler | Riley | Mk XI | | Pontiac | DP |
| 71 | Henzler / Farnbacher / Ehret / Price | Farnbacher Racing USA (USA) | Horst Farnbacher | Porsche | 996 GT3 Cup | | Porsche | GT |
| 73 | Liddell / Baldwin / Stanton / Tafel / Davis | Baldwin-Tafel Racing (USA) | Tony Dowe | Porsche | 996 GT3 Cup | | Porsche | GT |
| 74 | Dallenbach, Jr. / Dallenbach / Robinson / Unser | Robinson Racing (USA) | George Robinson | Riley | Mk XI | | Lexus | DP |
| 75 | Pechnik / Neiman / Van Overbeek / *Fogarty / *Long | Flying Lizard Motorsports (USA) | Johannes van Overbeek | Porsche | 996 GT3 Cup | | Porsche | GT |
| 77 | Gollin / Bobbi / Theys | Doran Racing (USA) | Kevin Doran | Doran | JE4 | | Lexus | DP |
| 78 | Bonham / Phillips / Orwicz / Williams / Fairchild | Farnbacher Racing USA (USA) | Horst Farnbacher | Porsche | 996 GT3 Cup | | Porsche | GT |
| 79 | da Matta / Bourdais / Newman / Brockman | Newman Racing/Silverstone Racing (USA) | Newman/Hall | Crawford | DP03 | | Ford | DP |
| 80 | Kitch / Gagne / Pickering / Pallis | Team Seattle/Synergy Racing (USA) | Kitch/Cole Scrogham | Porsche | 996 GT3 Cup | | Porsche | GT |
| 81 | Gaylord / Van Wijk / Murry / Emory | Team Seattle/Synergy Racing (USA) | Kitch/Scrogham | Porsche | 996 GT3 Cup | | Porsche | GT |
| 85 | Phipps / Hardage / Nahir / Mayer / Trentini | Condor Motorsports (USA) | Carlos Bobeda | Porsche | 996 GT3 Cup | I | Porsche | GT |
| 86 | Sellers / Urciuoli / Workman / Marshall | Synergy Racing (USA) | Cole Scrogham | Picchio | DP2 | | BMW | DP |
| 93 | Cosmo / Stewart / *Stewart / *Stewart / *Gilbert | TPC Racing (USA) | Gary Stewart | Porsche | 996 GT3 Cup | | Porsche | GT |