IDK, I just made this up an hour ago.
OK, rules.
You MUST run the first race and start the second. If a top team S&P's, they can deal with their sponsor and the boo's.
If you wreck your first car, you fix it during the first race or pull out a backup.
Using a backup in the second race follows the same rules as qualifying. If nascar says there is enough damage, you change under the usual start from the back rule.
You can choose to use a backup for the second race, but it will cost you 5 points.
Limit tires to enough for both races, but teams can decide how and when to use them.
Each team gets one extra set of a softer tire. They can only use them when there are a safe number of laps to go. Lets say Goodyear limits those softer tires to 25 laps. Teams would only have the option to put them on 20 or less to go. We will once again see tire strategy. But run them too long, and you'll be slow at the end.
What else?