Fastback is a term most commonly used in the automotive industry to describe a car body style with a sloping roofline that flows seamlessly down to the rear of the car. However, there are several other synonyms that can be used to describe this type of car or design. Some popular alternatives include coupe, sports car, two-door, GT (Grand Touring), and performance vehicle. Each of these terms also conveys a sense of speed and power, which is what makes the fastback such an appealing design for car enthusiasts. Ultimately, regardless of what you call it, there's no denying the undeniable sleekness and performance appeal of a fastback car.