PORSCHE RACING HISTORYTom Alan Marx (USA)
1980 : Sears Point 100 Miles - 3rd in class
27 April 1980 - Riverside 5 Hours - World Challenge for Endurance Drivers
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 31 | Porsche 911 Carrera RSR | GTO | Darrel Overstreet (USA)/Dennis Lanfre (USA)/Tom Alan Marx (USA) | RSR Associates (USA) | 14th | 4th | 36th | 145 laps |
27 July 1980 - Sears Point 100 Miles - IMSA - International Motor Sport Association
| No. | Car | # | Class | Drivers | Entrant | Pos | Class | Grid | Notes |
| 31 | Porsche 911 Carrera RSR | GTO | Tom Alan Marx (USA) | RSR Associates (USA) | 10th | 3rd | 17th | 36 laps |