Some cars are forgettable -- those metal boxes on wheels that simply get you from A to B. Then there are cars that you'll never forget -- the special ones that take your breath away. With its aggressive styling and an engine that can impress even the most jaded automotive enthusiast, you'll never forget the 2012 Ford Shelby.

The Ford Mustang has already been our top pick among the muscled-up pony cars, and the GT500 simply cranks up the power to supercar levels. With 550 horsepower underfoot, this mega Mustang spanks Dodge Challengers and Chevrolet Camaros in the quarter-mile. The Shelby furthers its lead when the road begins to twist, thanks to a well-tuned suspension and sticky supercar tires.

With a price tag approaching $50,000, though, supremacy doesn't come cheap. That's more than double what the plenty capable 305-hp Mustang V6 costs and almost $20,000 more than the already raucous Mustang GT. That's a lot of scratch for a Mustang, especially one stuck with an interior not much different from a well-equipped Mustang GT. Unimpressive interior materials and a tilt-only steering wheel are even more glaring oversights at this price.

But on the whole, these are minor blemishes next to everything that's great about the 2012 Ford Shelby GT500. It's a quicker thrill than the 2012 Chevrolet Camaro and the 2012 Dodge Challenger, and its backseat makes it more practical than a 2012 Chevrolet Corvette. No doubt it will be a fond deathbed memory for those lucky enough to own one.

The 2012 Ford Shelby GT500 is a four-seat high-performance coupe or convertible based on the Mustang. Standard features include 19-inch alloy wheels, high-performance tires, Brembo brakes, a rear spoiler, automatic xenon headlights, foglights, keyless entry, air-conditioning, cruise control, a leather/Alcantara-wrapped steering wheel, leather/Alcantara-upholstered sport bucket seats with racing stripes and Cobra logos, a power driver seat, a Sync multimedia voice control system and an eight-speaker audio system with a CD player, auxiliary/USB audio jacks and satellite radio.

The GT500 convertible also comes with a power-operated soft top. Both the GT500 coupe and convertible have side stripes on the rocker panels and hood stripes that run from nose to tail (but not over the convertible top). Ford offers a stripe-delete option for buyers who prefer a less ostentatious look.

Options include a glass roof for the coupe, leather Recaro front seats, an Electronics package (hard-drive-based navigation system, HD radio and dual-zone climate control), an upgraded "Shaker 1000" 10-speaker 1,000-watt sound system and the SVT Performance package (unique 19-inch front/20-inch rear wheels, a rear spoiler with a Gurney Flap, higher-performance tires, revised suspension tuning, unique stripes/rear spoiler and a 3.73 limited-slip rear axle).

The rear-wheel-drive 2012 Ford Shelby GT500 is powered by a 5.4-liter supercharged V8 that produces 550 hp and 510 pound-feet of torque. A six-speed manual is the only transmission available. Acceleration from zero to 60 mph requires only 4.4 seconds on its way to a quarter-mile time of 12.4 seconds at 116 mph. The EPA estimates fuel economy at 15 mpg city/23 mpg highway and 17 mpg in combined driving.

Standard safety features for the 2012 Ford Shelby GT500 include antilock disc brakes, traction control, stability control and front-seat side airbags. Ford's MyKey system (which allows you to limit the car's top speed and stereo volume) is also standard. A temporary tire-inflation kit replaces the spare tire.

In Insurance Institute for Highway Safety testing, the Mustang coupe received the top score of "Good" in frontal-offset and side-impact tests. In Edmunds brake testing, a GT500 with the optional SVT Performance package stopped in just 104 feet from 60 mph. The massive standard Brembo brakes also experienced no fade after multiple passes.

Fire up the 2012 Ford Shelby GT500 and you're treated to one of the meanest-sounding engines ever built. At idle, the slow rumble murmurs the potential for tire-smoking mayhem. Lay into the throttle and the rumbling becomes a boiling torrent, launching the GT500 forward accompanied by the supercharger's whine that can best be described as addictive.

In the corners, the GT500 is easily upset by careless inputs. Maximizing thrills in the curves requires a high level of restraint and a healthy dose of courage. There's plenty of grip, but the Shelby's 3,800 pounds seem poised to break loose at all times. The ride is stiff, but not too harsh in the base model.

Adding the SVT Performance package introduces plenty of harshness, though, and without the expected performance gains. On a polished-smooth racetrack, the SVT option might make sense. But in the real world -- and on real tracks -- it makes the car skittish. The upgraded tires also tend to snap loose from adhesion, and drift rather gracefully. For all but the most rabid track-day enthusiasts, we'd suggest skipping the SVT upgrade.

Except for some suede trim, Cobra badges and a cue-ball shift knob, the GT500 interior isn't much different from that of a well-appointed Mustang GT. The abundance of hard plastics and similarities to lesser-trim Mustangs in a $50,000 car is slightly disappointing. Gauges are slightly more legible than the hieroglyphics found in the Mustang, but both place the optional multifunction display too low in the center stack. Climate and audio controls are also small and hard to read at a quick glance; thankfully, the Sync voice-activated system nearly eliminates the need to bother. Outward visibility is best-in-class thanks to thin A-pillars and flip-down rear headrests.

Interior storage is notably scarce, with a shallow center armrest bin and a small glovebox and door pockets. The coupe's trunk can hold a generous 13.4 cubic feet of cargo, and split-folding rear seats allow you to load larger objects. The convertible lacks the folding seats and can only hold a maximum of 9.6 cubes.

Front seats are generally comfortable, although taller drivers may bemoan the lack of a telescoping steering column. Nearly any rear-seat passenger, regardless of size, will find scarce legroom among his or her chief concerns.