| 00 | Zitza / Thomasson / Lewis, Jr. / Wheeler | TZ Motorsports | James Thomason | Porsche | 996 GT3 Cup | | Porsche | GT |
| 01 | Pruett / Diaz / Papis | CompUSA Chip Ganassi with Felix Sabates (USA) | Mike Hull | Riley | Mk XI | | Lexus | DP |
| 02 | Dixon / Wheldon / Mears | Target Chip Ganassi with Felix Sabates (USA) | Mike Hull | Riley | Mk XI | | Lexus | DP |
| 04 | Sigal / MacLeod / Konôpka / Rosser | Sigalsport BMW | Gene Sigal | BMW | M3 | E46 GT | BMW | GT |
| 05 | Auberlen / Alhadeff / Milner / Marks / Sigal | Sigalsport BMW | Gene Sigal | BMW | M3 | E46 | BMW | GT |
| 06 | Archer / Reese / Oasis / Crescentini | Banner Racing (USA) | Leighton Reese | Chevrolet | Corvette | | Chevrolet | GT |
| 08 | Goldin / Goldin / Finlay / Richards / Thiel | Goldin Brothers Racing (USA) | Steve Goldin | Mazda | RX-8 | | Mazda | GT |
| 09 | Goad / Primat / Labonte / Oberto | Spirit of Daytona Racing (USA) | Troy Flis | Crawford | DP03 | | Pontiac | DP |
| 2 | Lammers / Patrick / McNish / Wallace | Howard - Boss Motorsports | Maxwell Crawford | Crawford | DP03 | | Pontiac | DP |
| 3 | Lewis / Szekeres / LaJoie / Burgess | Southard Motorsports | Steve Southard | Riley | Mk XI | | BMW | DP |
| 4 | Wallace / Leitzinger / Stewart | Howard - Boss Motorsports | Maxwell Crawford | Crawford | DP03 | | Pontiac | DP |
| 5 | Dayton / Knoop / DeVries / Matthews / Gue | Essex Racing | Michael Gue | Crawford | DP03 | | Ford | DP |
| 6 | Tracy / Mears, Jr. / Borkowski / Wilden | Graydon Elliott Fusion Racing with MSR | Michael Shank | Riley | Mk XI | | Lexus | DP |
| 7 | Franchitti / Duno / Franchitti / McGarrity | CITGO Racing by SAMAX (USA) | Peter Baron | Riley | Mk XI | | Pontiac | DP |
| 8 | Frisselle / Frisselle / Field / Huisman | Synergy Racing (USA) | Cole Scrogham | Doran | JE4 | | Porsche | DP |
| 10 | Taylor / Collard / Angelelli / Briscoe | SunTrust Racing (USA) | Bill Riley | Riley | Mk XI | | Pontiac | DP |
| 11 | Tuttle / Petty / Said | Tuttle Team Racing/SAMAX | Peter Baron | Riley | Mk XI | | BMW | DP |
| 12 | Fernandez / Haberfeld / Sharp | Lowe's Fernandez Racing | Tom Anderson | Riley | Mk XI | | Pontiac | DP |
| 14 | | Autometrics Motorsports (USA) | Cory Friedman | Porsche | 996 GT3 Cup | | Porsche | GT |
| 15 | Friedman / Small / McGehee / Martin / Herring | Autometrics Motorsports (USA) | Gordon Friedman | Porsche | 996 GT3 Cup | | Porsche | GT |
| 16 | Dyson / Dyson / Gavin / Smith | Howard - Boss Motorsports (USA) | Maxwell Crawford | Crawford | DP03 | | Pontiac | DP |
| 17 | Mowlem / Arnold / Sellers / Shep / Seyffarth | SAMAX (USA) | Peter Baron | Porsche | 997 GT3 Cup | | Porsche | GT |
| 19 | Gidley / McDowell / Barron | Playboy/Uniden Racing | Steve Cameron | Crawford | DP03 | | Ford | DP |
| 21 | Van Uitert / Connolly / de Quesada / Sutherland / Sutherland | Matt Connolly Motorsports | Matt Connolly | BMW | M3 | E46 | BMW | GT |
| 22 | Dumoulin / Longhi / Assentato / Pechnik / Thornton | Fiorano Racing | Giovanni Panico | Porsche | 996 GT3 Cup | | Porsche | GT |
| 23 | Long / Rockenfeller / Luhr | Alex Job Racing/Emory Motorsports | Alex Job | Crawford | DP03 | | Porsche | DP |
| 24 | O'Shaughnessy / Cotter / Malloy / Shalit / Johnson | Matt Connolly Motorsports (USA) | Matt Connolly | BMW | M3 | E46 | BMW | GT |
| 28 | Valiante / Finlay / Herta / Rice | Finlay Motorsports | Steve Cameron | Crawford | DP03 | | Ford | DP |
| 29 | | Xtreme Motorsports Group | Anthony Puleo | Nissan | 350Z | | Nissan | GT |
| 36 | Pobst / Pumpelly / Levitas / Baas | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | GT |
| 39 | Fittipaldi / Cheever, Jr. / Carpentier | Cheever Racing | Eddie Cheever, Jr. | Crawford | DP03 | | Lexus | DP |
| 40 | Fellows / Ruhlman / Bingham / Bell | Derhaag Motorsports (USA) | Chris Bingham | Riley | Mk XI | | Pontiac | DP |
| 41 | Nonnamaker / Nonnamaker / Nonnamaker / Gonzalez, Jr. | Team Sahlen (USA) | Mike Thomas | Porsche | 996 GT3 Cup | I | Porsche | GT |
| 43 | Allen / Hennessy / Michaelian / Matos / Nonnamaker | Team Sahlen (USA) | Mike Thomas | Porsche | 996 GT3 Cup | | Porsche | GT |
| 46 | Mason / Baughman / Connolly / Del Vecchio / Collyer | Michael Baughman Racing (USA) | Michael Baughman | Chevrolet | Corvette | | Chevrolet | GT |
| 48 | Seiler / Dubler / Hauser / DeFontes / Thiel | WTF Engineering | Gwen Petersen | Chevrolet | Corvette | | Chevrolet | GT |
| 50 | Zogaib / James / Nastasi / Gleason | Blackforest Motorsports | Brian Nott | Crawford | DP03 | | Ford | DP |
| 51 | Johansson / Hughes / Erdos | Cheever Racing | Eddie Cheever, Jr. | Crawford | DP03 | | Lexus | DP |
| 52 | Bertuzzi / Monzón / McCormick / Baron | Mastercar (I) | Mario Crugnola | Ferrari | 360 Modena | Challenge | Ferrari | GT |
| 55 | Arnold / Miller / Koselke / Poscente / Montgomery | ASC Motorsports | Zach Arnold | Chevrolet | Corvette | | Chevrolet | GT |
| 57 | Rice / Riggins / Stevenson / Trenery / Cicero | Stevenson Motorsports (USA) | John Stevenson | Chevrolet | Corvette | | Chevrolet | GT |
| 58 | Donohue / Law / Maassen | Red Bull/Brumos Porsche (USA) | James Bailie | Fabcar | FDSC/03 | | Porsche | DP |
| 59 | France / Barbosa / Christopher / Haywood | Brumos Racing (USA) | James Bailie | Fabcar | FDSC/03 | | Porsche | DP |
| 60 | Negri / Patterson / Allmendinger / Wilson | Michael Shank Racing | Michael Shank | Riley | Mk XI | | Lexus | DP |
| 63 | Spencer / Spencer / Mandeville / Grupp / Drummond | Team Spencer Motorsports | Reece Harper | Mazda | RX-8 | | Mazda | GT |
| 64 | Edwards / Collins / Pilgrim / Magnussen | TRG (USA) | Kevin Buckler | Pontiac | GTO.R | | Pontiac | GT |
| 65 | Lally / Bunting / Valentine / O'Connell | TRG (USA) | Kevin Buckler | Pontiac | GTO.R | | Pontiac | GT |
| 66 | Ortelli / Nearn / Sauvage / Johnson | TRG (USA) | Kevin Buckler | Porsche | 997 GT3 Cup | | Porsche | GT |
| 67 | Flanagan / Kroczek / Keith / Bullock | TRG (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | GT |
| 68 | Pace / Greist / Lowe | TRG (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | GT |
| 69 | Vargo / Vargo / Herrington / Refenning | TRG (USA) | Kevin Buckler | Porsche | 996 GT3 Cup | | Porsche | GT |
| 70 | Tremblay / Haskell / Altenburg / Ham | SpeedSource | Sylvain Tremblay | Mazda | RX-8 | | Mazda | GT |
| 71 | Lacey / Martini / Wilkins / Wilkins / Mowlem | SAMAX/Doncaster Racing | John Lacey | Porsche | 997 GT3 Cup | | Porsche | GT |
| 72 | Henzler / Liddell / Van Overbeek / Rahal | Tafel Racing | Tony Dowe | Porsche | 997 GT3 Cup | | Porsche | GT |
| 74 | Davis / Espenlaub / Lux / Tafel / Cawley | Tafel Racing (USA) | Tony Dowe | Porsche | 997 GT3 Cup | | Porsche | GT |
| 75 | Krohn / Jönsson / Bergmeister / Braun | Krohn Racing | Jeff Hazell | Riley | Mk XI | | Pontiac | DP |
| 77 | Barber / Borcheller / Jourdain / Brix | Feeds The Need/Doran Racing (USA) | Kevin Doran | Doran | JE4 | | Ford | DP |
| 78 | Zacharias / Bourdais / Boesel | Doran Racing (USA) | Kevin Doran | Doran | JE4 | | Ford | DP |
| 80 | Murry / Keen / Stanton / Pompidou | Synergy Racing | Cole Scrogham | Porsche | 996 GT3 Cup | | Porsche | GT |
| 81 | Pew / Marshall / Prewitt / Marshall / McCrackin | Synergy Racing (USA) | Cole Scrogham | Porsche | 996 GT3 Cup | | Porsche | GT |
| 82 | Werner / Peter / Quester / Riccitelli | Farnbacher Racing/Farnbacher Loles | Horst Farnbacher | Porsche | 997 GT3 Cup | | Porsche | GT |
| 83 | Farnbacher / Fitzgerald / Ehret / Basseng | Farnbacher Loles/Orbit Racing | Gregory Loles | Porsche | 997 GT3 Cup | | Porsche | GT |
| 84 | Dallenbach, Jr. / Robinson / Dallenbach / Brassfield | Robinson Racing | James Fraser | Riley | Mk XI | | Pontiac | DP |
| 86 | Kitch / Pennington / Gagne / Pallis | Synergy Racing (USA) | Cole Scrogham | Porsche | 997 GT3 Cup | | Porsche | GT |
| 87 | Gaylord / Hill / Hill / Diefenbach | Synergy Racing (USA) | Cole Scrogham | Porsche | 997 GT3 Cup | | Porsche | GT |
| 89 | Dalziel / Fogarty / Figge / Empringham | Pacific Coast Motorsports | Tyler Tadevic | Riley | Mk XI | | Pontiac | DP |
| 92 | Stewart / Stewart / Gilbert / Stewart / Ave | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | GT |
| 93 | Ave / Stewart / Stewart / Gilbert / Stewart | TPC Racing (USA) | Michael Levitas | Porsche | 996 GT3 Cup | | Porsche | GT |
| 99 | Gurney / Stallings / Vasser / Moran, Jr. | Gainsco/Blackhawk Racing (USA) | Bob Stallings | Riley | Mk XI | | Pontiac | DP |