[Kevin M]

I dunno... I'm of the opinion that autocross is harder on the drivetrain than road racing is. The inputs and demands made of the chassis on a track are less frequent and generally smoother/slower than at an autocross. At least with me behind the wheel, heh. :o Sometimes there are "drag starts" at Solo 2, maybe not a full-on 6000 RPM clutch-dump, but still higher shock loading than a quick street start would have. And if you're forcing the shifter into gears, being very abrupt with clutch takeup, poorly rev-matching downshifts... there's plenty of room for bad things to happen.

Four full-throttle upshifts on the drag strip plus the launch is probably worse on the drivetrain than a whole day of Solo 2, but I still think that in terms of mechanical issues, hot lapping on a track is less stressful on the car.

I never tell people new to autocrossing that it's easy on the car, but I also don't think it's particularly bad. If you have minmal mods (stock classes, or underprepared ST/SP) and something breaks, it's a gray area as far as warranty claims go. You're not an asshole for expecting the dealer to fix what gets broken... but you also can't raise hell if they refuse because you autocrossed IMO. Now, if they just say "oh, you abused the car" in general but don't cite autocross specifically... they're in the wrong. splitting hairs maybe but I think there's an important distinction.