Compared to your average flight sim GPL uses very few keyboard commands, so
here are a few ideas for the 'F' keys.
A vignetted 'goggle' view, showing in peripheral vision the edges of the
drivers goggles. Add to this a reduction in vision if following close behind
another car for any length of time to represent oil/debris smearing. Jack
Brabham was known for driving in the dirt at the edges of the track to
distract pursuers, so what about a cracked lens in one side of your goggles?
And a key to wipe your goggles clean, or pull on another pair, many drivers
took two. And maybe the odd fly hitting your goggles would add more realism,
and appeal to the Quake minded players for a bit of gore?
Steve