I would love to see the return of URD GT/LMP races. Le Mans and road America were probably the most popular events in rf2 club last year. A field of gt3, p2 and p1 was great too.
Outside of that it would be great to run some gt500 events.
Some nice races with pit stops would be great is what I'm saying. Personally, not a huge fan of enduracers mod though, especially since it's already used in RDLM. It would cater to weirdos like me who just can't stand how broken enduracers appears.