http://www.youtube.com/watch?v=_LnmD7kxHUw&feature=player_embedded
“You get what you pay for,” and when it comes to rear spoilers, disaster can strike if they’re not carefully engineered. Look at the chaos below that was caused by a faulty wing. Was a cheap spoiler responsible for this disaster, or just bad luck?
Going 70 on the highway, will a big-ass wing on your Subaru make a performance difference? Sorry, no. How about if you're heading into the esses at VIR without realizing your ex-big-ass wing has just failed? Uh-oh…
It turns out that you need plenty of downforce on a WRX STI's rear wheels when you're pushing 150 on the race track, and Bad Things happen when your carbon-fiber wing goes AWOL without letting you know. We're happy to report that the STI pilot walked away from the wreck, though we're still shedding a few few tears for the poor car. The tale of Subaru racer Phil Grabow's not-so-happy adventure in Virginia may be read over at the NASIOC forums; here's an excerpt:
" With the new engine tuned we headed off to the second round of the NASA season at Virginia International Raceway. One of the major changes we made to the chassis was to have taller wing supports made so we could get the rear APR wing up into clean air in hopes of gaining down force. We also had added a rear diffuser to the flat panel underneath the car. After running at minimum power for practice and scrubbing in new tires the car felt great and the power delivery was awesome.
As we headed out for time session one disaster struck on the first lap! I was taking it easy to get the tires up to temperature but as I exited turn 6-7 the carbon wing structurally failed between the air foil and the mount. Not knowing this I entered the uphill esses at around 148 mph and this is what happened."
carbon fiber nowadays. guess it isn't made of magic after all. 
