Alright. This may sound crazy, but bare with me.
Thee S^4 cars make for great racing. But I don't think that they would be well suited to an online series.
Crazy talk, right? Well here's where you've got to bare with me. For me, at least, part of the joy in the S^4 racing was that noone took anything to seriously. If someone spun, it was "whatever, I'll get back in in the next race", not "FUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU". I think that adding in the pressures associated with running a true series will negate some of these aspects. The S^4 cars made for great, close, racing, but let's be honest, there was a LOT of contact (remember my brake light counting?), and I think that a serious series racing environment wouldn't allow the same degree of fun contact. That said, I'd love to run them with you guys just for fun. That is what they are truly exceptional at; fun.
Just my $.02.