Hi
Maybe Piboso, you could include a selection in your menu were you can have the option of "Time Of Day", so players could have the full experience in a sim with night racing.
You could include the factor of the grip... the kart may be a bit more oversteery :P and the track temp could be cooler as the day turns into night.
This would also include the factor of day progression... so you start off at 1pm and slowly moves into the night.
So 30 or 20 mins for us in real life would be 1 hour in the game! :)
Just another option you could think about... :)
Robby_21