I did it once last year at a local autocross with my buddy because my camaro was getting some work done to it. I am a goid driver with a lit of racing background including motorcross/flat trackig a quad, shifter carts(raced at atlanta, mid ohio, and others), super motard, and road racing my camaro. When I got out there, I embarrased myself, it was not the first time I had autocrossed either. I have an SC, and it did well on the 2 sweepers, but any s-shaped or shicanes, hores shoes, and the "loop" they had, there was too much body roll, way too much understeer, and the tires could not hold. I did not have the worst time but only a second off. I am still planning to autocross it again, thats why I got in on the KSport Group Buy, I just put on X-Drilled/slotted rotors and good pads(cant afford the Rotora BBK's), will be getting rear LCA's, Engine Dampner, Buddy Club short shifter, amongst any other things to help.
I too want to make people go "WTF" when the see a box going crazy. I will also be getting an intake and exhaust down the road for better throttle response and turn exiting power, even though the 5 speed has decent gearing for down low, I never went pass second gear.
Any more questions, just ask, I am here to help.
Also if you are definately going to do it, get GOOD tires, I have on Dunlop Sport A01's now, and I can take my exit to work almost 8mph faster, the badyears suck!
) while being pushed through those turns. 
