Shake, rattle, and roll may be a great tune for an oldies station, but it by no means describes the feeling you get when you drive the droptop version of Ford’s new-generation ponycar. From the start of the program, Ford engineers designed the convertible alongside the coupe, resulting in a car that has more than twice the torsional stiffness of the previous-generation Mustang. Steering-column shake and cowl quiver over railroad tracks and potholes, common bugaboos of many convertibles on the road today, are held largely in check. The insulated fabric top seals out noise better than its predecessor allowing conversation at normal levels while cruising. Unhook two front latches and press the electric switch on the windshield header, and the open-air four seater moves though the air with less buffeting than previous Mustangs. The best news of all, Ford expects to price the V-6 convertible around $25,000 and the GT V-8 ragtop near $30,000, yet another reason to go topless in a Mustang.