I don't know about you guys, but I noticed EXTREMELY slight differences in handling between each manufacturer (Ford, Dodge, Chevy, and Toyota) in tight circuits; WAAAY back when the NASCAR Seasonal event was out, I noticed that one brand had the slightest touch of understeer in the corners, one seemed less grippy, and on seemed to have the slightest touch of oversteer with no grip loss (I don't remember which manufacturer corresponds to which characteristic). This wouldn't matter really on an oval; it's really just situations when you're heavily braking or accelerating in or out of a sharp corner, like on Rome. Otherwise, every car seems the same. I don't really have a way of proving this do I? It's hard to visibly SHOW how a car over/understeers at this level of subtlety.