Pick of the Day: 1968 Mercury Cougar XR-7 listed for sale on ClassicCars.com by a dealership in Lake Havasu City, Arizona.Mercury Cougar XR-7 featured a 390 V8 engine providing 320 horsepower and deluxe features like hidden headlights and sequential taillights.Introduced in 1967, Mercury XR-7 was marketed as a 'luxury interior model' with upscale features targeted at admirers of expensive foreign cars.1968 Mercury Cougar XR-7 had a rare 390 two-barrel engine with big-block torque and limited production, priced at $49,500 on ClassicCars.com.