I think the IROC series really lost is way and that is why it left a lot of bad tastes in peoples mouths. The last year they ran it they actually ran the road course at Daytona which was at least different.
I recently found an old video of the NASCAR invitational race at Suzuka on Youtube and that really had potential. It would be cool if when the Aussie V8 guys come to the US again they have an enduro race or two with NASCAR and Indy drivers as the second drivers. Maybe have a race in conjuction with the Indy Long Beach GP with Indy and Tudor Sports car drivers as the seconds. The next time they come to Austin maybe have it on a free NASCAR Sprint Cup weekend and get some of the Cup drivers to be the second drivers.