Interesting. My 65 Barracuda was built December 4, 1964 (in St. Louis) and its parking lights have always come on with the headlights. I have always assumed that all 65 Barracudas were the same way, but as I've found out with other cars I've owned, just because my car is a certain way doesn't mean that's true of all cars of the exact same model equipped in pretty much the same way and maybe even built in the same plant at about the same time.