My test is would my father or others of his generation have tried to race it if they had access to it.
When you look at the history of hotrodding and land speed racing you see in the early days that they did some very wild things to go faster. They didn't let convention and the norms of the day stand in the way of their quest for speed.
Some where in the last few decades that open attitude of figure out a way to go faster has slowly been overtaken by rules that cast in concrete one specific way of doing it. Time and technology changes and the racing classes should have room for similar cars using currently available technology that can compete for a record.
Time only is fine for a one off car that wants to try something, but when you create rule sets that outlaw entire classes of current production cars or current technology I think it is a step in the wrong direction.
I do understand the logisitical challenge of coming up with a rules package for a new class especially the proposal of a NASCAR class. I do also understand the problems with class proliferation and over popularity.
But I also think it is important to ask the questions that help define what classes make sense, and if certain classification decisions are really appropriate for the available equipment that the racer has access to today.
Since NASCAR bodies are all one off, there would be a major challenge to standardize body shape.
There are two ways to deal with that, One would be to force them to run to a specific template, or the other option is to "maintain the as raced appearence" but let them have a free hand with minor tweaks, by setting only height and width requirements.
In the vintage Oval Track class that is exactly what they do by the phrase:
... the appearance and design of cars in this catagory must be practical for, and as were used in, OVAL TRACK and SPEEDWAY competition.
Simple to document, provide pictures of a car (this specific car) in original competition trim and if it appears "as raced" and meets a width and height limit -- let it race. Part of the spirit of the competition would be to see if the track cars were given free reign on things like spoiler height and angle how fast could they have gone on a unlimited length straightaway?
Larry