I'd love to see a 12 hour race on Trial Mountain or Monza for cars with around 500 to 550pp with full damage and opponents that randomly used any of the sports tires so choosing your tires had more strategy.
I'd love to see a short enduro (100 lap race) on Deep Forest as well.
And if I could really have anything, I'd like to see endurance races for Spa, Hockenheim, Silverstone, Motegi, Atlanta, Sebring, Infineon, St. Pete, Midfield, Apricot Hill, Seattle, Tahiti Circuit, Costa d'Alfi (can't spell), Smokey Mountain (lol), and Red Rock Valley. Surely that's not too much to ask!
EDIT: Whatever the super long version of Tahiti was called.