Screw the classes. Make your car the way you want it. Making a car legal for a class it will get run in maybe 2 times a year is stupid. The class rules hold the cars back if you are trying to be competitive in other heads up racing classes you can encounter on a weekly basis at your local track.
My car has too big of a turbo for TSM, too racey for TSE, and too slow (under turboed) to be competitive in TSL. I bracket race and mess around on the street more than I find myself at a Buick event with these classes.