I think the OP's idea is great !
Unfortunately, the NHRA is not run by racers anymore and is not the only game in town now.
The young blood is into the NMRA, NMCA, LSX series, etc.
If there was a class for only 2008 and newer Mustangs, Challengers, and Camaros, I would definitely be interested in buying a new Mustang and participate.
As it stands righ now, the NMRA is the only choice for Ford fans with new Mustangs.
I am an optimist, but sadly, I believe NHRA has really messed up the sportsman ranks. Maybe beyond repair.