As D Day said, I don't have a dog in this fight but from the way I see things looking from the outside in..
The ALL stock appearing is what makes this class cool!!! I have taken a few guys with TR's to look at Bill's car, they see the all stock appearing and THEN I tell them it has run in the 10's. They are dumbfounded. If control arms, valve cover spacers, cold air intake, ect, ect change happens I feel it will take away from the class cause the guys that DO know TR's will spot it...see my 1st point.
It's going to be tough to get a guy that has modded his car past TSA to go back. They may build another car but a guy that has not modded past TSA or bought a stocker would likely go for the class. This all depends on how fast one wants to go so the car count, I feel, will never be as high as lets say THS or XTSM.
A guy, such as myself, did not want to deal with the restrictions of a stock air box, downpipe, appearing turbo, ect.ect. I want to go fast. Until I added my front mount IC most of the local guys at the track probably thought it was a "stock" car. Guys like Kip could see from a mile away it wasn't. Guess it all depends on who your trying to impress or how much you want to challenge yourself in a "restrictive" class. The guys that know how hard it is to run a low # in stock appearing fashion will be the ones that respect it the most.