The problem seems to be caused by high framerate. To cap the maximum framerate on systems that use NVIDIA graphics cards-

1. Search and open NVIDIA Control Panel

2. Click on "Manage 3D settings"

3. Click the "Program Settings" tab

4. Click the "Add" button in the "Select a program to customize" section and locate the Dirt 3 executable to add it as a program to customise. This can be found by going into Steam and right-clicking on the game, Manage -> Browse Local Files and finding "dirt3_game.exe"

5. In the "Specify the settings for this program section, scroll to and locate the "Max Frame Rate" option. Click on this option to open a menu that should specify three radio buttons, "Use global setting", "Off" or "On"

6. Select the "On" option and adjust a slider to your preferred framerate. Has been tested successfully at 240fps which is what I would recommend.

7. Hit "Ok".

8. Hit "Apply" that should appear on the bottom-right of the control panel.

9. Restart and enjoy the game.