(And don't make it something like FF challenge, or Le Mans, or something else, we'll know that (should) be in the series, but more for the one makes that GT3 had to offer, (but base it off your wishlist for cars and tracks).
Use this Format:
League
Race Title
License/Level
Single Race/Championship
Cars allowed
Specific Guidelines (tires, horsepower limits, etc.)
Race/Laps
Race/Laps
Race/Laps
Race/Laps
Race/Laps
Prize money for each place
Prize Car
My Example:
Extreme League
The Classics Reunite
Championship
Cars Allowed:
Traditional GT-One Race Car
R390 GT1 Race Car
Mazda 787B
No Regulations
RACES:
Grand Valley Reverse: 15 Laps
Laguna Seca: 15 Laps
Indy/Road Course: 15 Laps
Le Mans 2009 No Chicanes: 15 Laps
SSR11: 15 Laps
Cote D' Azur: 20 Laps
$ Per Race:
1st: 50,000
2nd: 10,000
3rd: 7,500
4th: 3,000
5th: 1,000
6th: 100
$ for Overall:
1st: 300,000
2nd: 100,000
3rd: 10,000
4th: 5,000
5th: 2,000
6th: 1,000
Prize Car:
Toyota TS030 Hybrid
(If your a GT3 fan you should get this right away)