Here's a helpful tip for slow motion controls

Change your controls with controller by removing left and right on D-pad and place slower motion on left and faster motion on right button. I hope that was a helpful tip compared from using keyboard configuration for slow motion

 

Where do i map reset car and load home position then

 

Insert is reset car on keyboard default
R is restart on keyboard default
You can use it on keyboard since it may not be as important to hit as fast as the slow motion button is

but if you'd like you can always change it to somewhere easier to get like select ( removing change camera to a botton on keyboard. And same with start since pausing isn't rlly nessesary in free roam
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Only if the keypad on 360 controller worked properly in games... endless possibilities