The 2003 ASCAR Season was the third season of United Kingdom-based NASCAR style stock car racing, originally known as ASCAR. From this season 'Days of Thunder' was adopted as a promotional brand inspired by the NASCAR based movie of the same name. It was used alongside the ASCAR brand for the 2003 season before taking over entirely from 2004.
| Team | Car | Driver | Rounds | ||
|---|---|---|---|---|---|
| Kidd-Richardson Racing | Chevrolet | 2 |  Shaun Richardson | All | |
| RML | Chevrolet | 4 |  Alejandro Lince | ||
| 33 |  Peter Falding | ||||
| 44 | Anthony Swan | All | |||
| 48 |  Steve Grissom | ||||
| 84 | Ben Collins | All | |||
| Team West-Tec | Chevrolet | 5 | Rob Speak | ||
| align=center rowspan=2 | 42 |  Niklas Lovén | |||
| Chris Cooke | |||||
| Ford Pontiac | align=center rowspan=2 | 96 | Michael Vergers | ||
| Derek Hayes | |||||
| Xcel Motorsport | Pontiac | 6 | Stevie Hodgson | ||
| 7 | Andrew Kirkaldy | ||||
| Fast Tec Motorsport | Pontiac | 12 | Mark Proctor | All | |
| Shark Racing | Chevrolet | 17 | Tony King | ||
| TorqueSpeed | Chevrolet | 24 | John Mickel | All | |
| 25 | Ian McKellar Jr. | All | |||
| 26 | Oli Playle | All | |||
| Shearspeed | Pontiac | align=center rowspan=2 | 39 | Andy Smith | |
 Phiroze Bilimoria | |||||
| Intersport Racing | Pontiac | 40 | Kevin Clarke | All | |
| Scott Racing Services | Chevrolet | 66 | Kieran Dynes | ||
| Team HTML | Pontiac | align=center rowspan=3 | 68 | Earl Goddard | |
 Max Papis | |||||
| Derek Hayes | |||||
| 69 | Roland Rehfeld | All | |||
| Steward Racing | Ford | 75 | John Steward | All | |
| Team Catchpole Racing | Chevrolet | 77 | Phil Weaver | All | |
| CWS Racing | Chevrolet | 78 | Colin White | All | |
| align=center rowspan=2 | 79 | Chris Cooke | |||
| Andy Smith | |||||
The season consisted of eight meetings with either one or two races taking place at each. The grid for the opening race of each meeting was set by a qualifying session with the second race grid being set by the finishing order of the first. Two meetings were held at the EuroSpeedway in Germany with the remaining six at the Rockingham Motor Speedway in the United Kingdom.
| Pos | Driver | | | | | | | Pts | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| R1 | R2 | R3 | R4 | R5 | R6 | R7 | R8 | R9 | R10 | R11 | R12 | R13 | |||
| 1 | Ben Collins | 4* | 2 | 3 | 2* | 3* | 1* | 5* | 1* | 1* | 1* | 11* | 1* | 1* | 2299 |
| 2 | Colin White | 6 | 5 | 10 | 6 | 5 | 7 | 3 | 6 | 4 | 2 | 1* | 5 | 4 | 2044 |
| 3 | Michael Vergers | 1* | 3* | 3 | 2* | 3* | 1* | 13* | 5 | 11 | 6 | 4 | 5 | 1963 | |
| 4 | Roland Rehfeld | 7 | 1* | 9* | 17 | 7 | 10 | 2 | 3 | 2* | 9* | 10 | 3 | 6 | 1962 |
| 5 | Ian McKellar Jr. | 20 | 13 | 4 | 1* | 1* | 12* | 15 | DNS | 3 | 3 | 2* | 2 | 2 | 1821 |
| 6 | Anthony Swan | 15 | 11 | 11 | 8* | 11 | 15 | 10 | 5 | 7 | 4 | 3 | 8 | 7 | 1804 |
| 7 | Mark Proctor | 12 | DNS | 8 | 7 | 6 | 2* | 6 | 2 | 9 | 6 | 5 | 9 | 19 | 1722 |
| 8 | Phil Weaver | 10 | 6 | 13 | 12 | 10 | 5 | 19 | 17 | 16 | 14 | 14 | 17 | 10 | 1567 |
| 9 | Shaun Richardson | 18 | 17 | 20 | 10 | 16 | 9 | 9 | 4 | 6 | 15 | 15 | 18 | 12 | 1546 |
| 10 | Oli Playle | 3 | 4 | 19 | 16 | 15 | 8 | 21 | 18 | 13 | 7 | 13 | 23 | 22 | 1509 |
| 11 | John Steward | 15 | 10 | 16 | 18 | 18 | DNS | 8 | 8 | 15 | 13 | 9 | 12 | 13 | 1421 |
| 12 | John Mickel | 19 | DNS | 7 | 5* | 12* | DNS | 17 | 16 | 8 | 5 | 4* | 21 | 16 | 1390 |
| 13 | Andrew Kirkaldy | 14 | 12 | 12 | 15 | 4 | 14* | 17 | 10 | 8 | 7 | 20 | 1363 | ||
| 14 | Kevin Clarke | 21 | DNS | 6 | 19 | 9 | 6 | 11 | 11 | 14 | 8 | 7 | 22 | DNS | 1351 |
| 15 | Rob Speak | 8 | 8 | 1* | 4 | 14 | DNS | 18 | DNS | 11 | 6 | 3 | 1278 | ||
| 16 | Alejandro Lince | 5 | 16 | 5 | 13 | 13 | 16 | 14 | 15 | 12 | WD | WD | 1116 | ||
| 17 | Andy Smith | 13 | 14 | 20 | 7 | 10 | 12 | 12 | 19 | 18 | 1034 | ||||
| 18 | Stevie Hodgson | 2 | 15 | 2 | 9 | 17 | DNS | 16 | 17 | 1020 | |||||
| 19 | Tony King | 11 | 9 | 21 | 19 | DNS | 12 | 9 | 15 | 14 | 923 | ||||
| 20 | Derek Hayes | 17 | 4 | 4 | 16* | DNS | 19 | 14 | 8 | 892 | |||||
| 21 | Niklas Lovén | DNS | 18 | 18 | 11 | 8 | 11 | 18 | 13 | 21 | 891 | ||||
| 22 | Chris Cooke | 15 | 14 | DNS | 14 | 7 | 12 | 610 | |||||||
| 23 | Kieran Dynes | 13 | 10 | 20 | 10 | 9 | 603 | ||||||||
| 24 | Earl Goddard | 9 | 7 | 280 | |||||||||||
| 25 | Peter Falding | 11 | 11 | 252 | |||||||||||
| 26 | Phiroze Billimoria | 20 | 15 | 200 | |||||||||||
| 27 | Max Papis | 14 | 114 | ||||||||||||
| 28 | Steve Grissom | 17 | DNS | 102 | |||||||||||