For 2011, the Shelby GT500 is just plain awesome. Really, it was awesome last year too. But now it's 200 pounds lighter than the 2010 model, thanks mostly to an aluminum engine block, and has 10 more horsepower squeezed out of the blown 5.4-liter V-8. The powerplant now makes an unbelievable 550 hp -- 45 more than a Chevrolet Corvette Z06.
I'm always of two minds when I drive the Shelby GT500. One part of me revels in its tire shredding, supercharged V-8 glory. For all the whining you'll hear about the live rear axle, it does an absolutely fantastic job putting 550 horsepower to the ground-provided that ground is relatively smooth. It's also more fun than any muscle car should be on curvy roads, where the 200-pound weight loss is definitely noticeable and appreciated. The Mustang's interior is a bit out of its depth for this price range, but is still great looking and well-assembled.
On the other hand, $55,330 is a lot of money. Chevrolet Corvette Gran Sport money, actually. In my opinion at least, a well-sorted muscle car like the GT500 is still no match for a well-sorted sports car like the 'Vette. At the other end of the spectrum, the Mustang GT we had in the office recently was about $20,000 less, and was very nearly as much fun to drive.
Even if I had $55 grand to spend on a fun car, the Shelby GT500 would be a very bad idea for me, since I'd surely soon be in jail with the car confiscated... It's just so easy to find yourself going WAY faster than the speed limit, sometimes in a haze of tire smoke.