“For horsepower, performance and price, I donÂ’t see anything else out there,” says automotive legend Carroll Shelby, talking about the competition for the 2007 Ford Shelby GT500 Convertible. “I donÂ’t know anywhere you can get nearly 500 honest horsepower with four seats.” Love the new-look Mustang? Love the thought of having a thumping 475-horsepower (estimated) American supercharged V-8 in a convertible? Interested in accelerating from a standstill to 60 mph in around 4.5 seconds ― for around $44,000? We thought you might ― thatÂ’s why we couldnÂ’t resist putting this mighty new Shelby Mustang on our cover.