The "GT Sport Coupe" being offered as a prize at the Expo 1971 is a De Tomaso Pantera. Ford Motor Company provided vehicles for the show (like Cannon's car) and also owned part of De Thomaso, so for TV shows in the early 1970's, they would often provide a Pantera whenever a show needed a sports car.
The outdoor scenes at the "Expo 1971" were filmed at The Del Mar Fairgrounds