I'm sure I'm not the only one to have noticed, but there is a 1963 Riviera in "The Twilight Zone", Episode 123, "Nightmare at 20,000 Feet". As William Shatner is carried down the aircraft stairs, the car is parked next to the ambulance. It could possibly be a 64, but the air date was October 11, 1963, so it's doubtful.