@Rick,
That's one of the reasons I like the idea of either using 21.5 and 2s, like the F1 cars, or going with 1s and something like a 17.5, like the Spec175GT folks.
@RobK, I have been wondering how the USVTA 25.5 motor rules would work with these cars. At the moment, we have a spec tire. Limit the bodies and ESC rules, and it would be QUITE similar to a pan car VTA.