[Billy Nees]

Mike, no matter what you do regarding rules, a handfull of racers will exploit the rules and dominate. In order to get any kind of series off the ground it has to have participation. The only way to get a significant number of participants, IMHO, is to make participating easy, convenient and inexpensive. Once you get them to try it, they can make their own decision as to whether they want to better their combination and continue or not. The trick is to get them to try it and the more that initially try it, the better chance the series has of surviving. After the series gets underway and gets (hopefully)a following then you can get feedback from those participants in regards to how or if the rules should be changed. But only active participants should have any say in any changes(see X-Techman post).
From my experiences, racers eventually get bored and want to try something different be it a local Bracket racer trying some .90 racing or an NHRA Stock or SS racer trying Nostalgia or a circuit. You have to make it quick and easy to set the hook. There are too few racers with the time, money and knowledge to do a purpose-built car on a whim.