I took the Yaris to the autocross today. It was held at Portland International Raceway, and was put on by Willamette Motor Club and the Alfa Romeo Club. Above is a video of part of run.
On the entire course, I could stay in first gear, thanks to the tall gearing. When I did have to shift into second, there wasn't much there -- hey, it's geared tall and has just over 100 hp; what do you want? The Megan Coilovers and TRD rear bar did a good job of keeping things in check. The course had some pretty decent sized dips/bumps, so you can hear the driver's-side front wheel rub just a bit over a dip. Overall, I think the Yaris did pretty well. And hey -- I beat my buddy Craig's Sentra SE-R Spec-V in one run (Sorry Craig, I had to mention it! To be fair, he was faster overall.). The Falken Ziex 912 tires did pretty well, although they certainly aren't optimal for autocross. Below are a few pics:
There were a couple of other neat subcompacts at the event, too. One was a very modified Ford Fiesta on race rubber, gutted, with a Mazda MX-3 engine in it, the other was an older Fiat (I don't know much about it).