A couple of years ago I saw a '99 Silver Viper at the Spring Mountain track (Chevy sponsored). Chevy owned the Viper and was testing it against a "top secret" new Vette. Looking back, it must've been the Z06. According to the engineers, the new Vette was quicker around the track than the Viper (oops).
Then, 6 months ago I was at Willow Springs the day Motor Trend tested their souped up turbo Focus (and Cobra FR500) against a Z06. Ford actually owned the Z06 and also had a '99 black Viper there. I guess their Viper lost the brakes at Road Atlanta so they fabricated brake ducting out of aluminum for the car. To this day I've never seen cooler brake ducts on a Viper.
Ford, like Chevy, was myopic about their car's (FR500) ability to beat the Viper around the track. Their #1 test driver was turning laps easily 7-8 seconds off the pace of a number of Viper Days competitors and complaining about how bad the handling of the Viper was. The Ford guys, though, were as nice as could be and didn't seem bothered in the least by our questions.