What’s a Mustang fan to do if 300, 400 or 500 horsepower isn’t enough? Or if you want a high-horsepower ride with a convertible top or an automatic? You call Shelby. In case you didn’t know, Shelby tunes Mustangs. How thoroughly Shelby mods your pony car are depends on your patience level and the size of your bank account. Shelby will sell you parts so you can go the work yourself one mod at a time, or you can send your ‘Stang to Vegas and they’ll do it all for you.