I have made a change to push all controllers into Steam Input by default for Saturday Night Racing. This should alleviate a known issue with input mappings not configuring correctly on some controllers. Gamepad controls will only function in race for driving mechanics at this time - the menus rely on the mouse.
If you encounter any issues please list the controller type and symptoms of the issue here. I can only test for controllers that I own and not every possible controller out there.
Thank you!