I’ve wondered about that given the promotional films. My coupe (the one I’m attempting to restore) is an LA car, but my convertible came from Hamtramck. From what I can tell they were only available from just after the end of the Dart Charger run to the end of the 1965 model year, or early summer. I’m sure you‘re correct about the stripe, because I was able to obtain a copy of a factory bulletin on how to paint the stripes, both the centered and offset version. All of which makes you wonder how a convertible GoGo (the one that belonged to the girl I knew) and a coupe wound up in Oklahoma City in 1966-67. Where did you get your information about GoGo’s being west coast only? I believe it to be true, but I’m really trying to gather some information and sales history about these cars. If you’re correct, I’m willing to be that there were a small number of dealers pushing them. Maybe some west coast version of Norm Spaulding, perhaps?