STO was WC GT, not TC. GT fits the type of car Kirk is describing as "not a touring car". STU was TC and if there were a few non touring cars there, too (I cannot think of any, and I was a huge fan of the series back in the days of Speedvision/channel - I remember BMWs, mazda6, proteges, focii, audi A4s, etc...) then just remember that in pro racing the balance was maintained actively and changes made between races were commonplace in that effort and if it allowed a manufacturer to come and play... we do not have that ability with the way the ST rules are written, so another way to weigh down or exclude "inherently better" cars is being discussed / requested. these are not very numerous chassis, it wouldn't be hard to identify them and specline adjust them via weight% change as needed, and such a method makes tools available to deal with things like "advanced" struts that I know Andy so keen on pointing out, without drawing arbitrary lines that affect all strut cars from a given manufacturer (or whatever descriptor) because of key examples they share a badge with. singling out a known chassis is a way to balance it with the more traditional chasis of the same arrangement than is any attempt to further categorize that chassis with the few similalrly higher performing ones.