The research was conducted by owner interviews, actual test drives, online reviews and results from independent testing.

The first thing you'll notice about the American icon is its lackluster interior without even comparing it to anything. Ford could have spent more time and effort setting the Shelby version apart from a regular mustang, even the Shelby stripes are a dealer option on some versions of the car. The GT500 does deliver in the area of power, and thanks to a supercharged engine, that power is loud, whining, and roaring at times. In both track tests and road tests the body of the GT500 was not as connected as one might expect. The 500-horsepower engine can do a great job of throwing the car around, but it also throws the car around, such is the curse of muscle without refinement. The styling of the GT500 is crispy and brawny, color schemes are good and the overall boldness that Ford brings can intimidate many competitors.

BMW not only upped the ante with it's newest 3-series but delivered well. The 335i is technology used correctly. The powerplant in the BMW is 200-horsepower LESS than the Ford Shelby GT500, yet it keeps with the GT500's speed and acceleration. This is due mostly to BMW's naturally aspirated inline-6 and dual scrolling sequential turbos. Even more suprising is that the prices are so very close for these two cars. The styling on the 335i, has changed, but a few owners believe it is still a bit sleepy, and understated. The materials in the interior are squarely on point. Perhaps most impressively in the driving department is that the BMW's automatic (with optional paddle shifters) performs more like a stick than the GT500 does. The shifting is nearly unnoticeable until you mash the gas pedal from a low speed, and even then, the BMW does not complain, it quietly obeys. All of the standart BMW amenities are in place including the misunderstood iDrive. The build quality of the BMW is noticeably better than the GT500's which is due mostly to the fact that the 3-series has been in production much longer than this incarnation of the Mustang series, so BMW has had ample time to refine, refine, refine all the flaws and designs.

In deciding to purchase one of these cars, a few important considerations should be made. Are you a diehard Amercan Muscle fan, if so this is a great car for you. The Ford's big engine stays thirsty and like most muscle cars the GT500 sometimes lacks the grace that come with lots performance cars. A huge consideration is the money. For Ford money you could own a BMW, which rarely been the case in the past. The 335i is not an M-series (M3) but behaves just like one only better because it ten-thousand dollars less. As a long term investment, the build quality could become an issue, especially since there now more collectible versions of the Mustang becoming available.