Family had one of that same model year I believe.....unfortunately as a teenager I totaled it. 🙁

Wait I take it back not that model year but close... ours was a '66

that IS a 66... but it's technically a Cobra, not a Mustang. The Mustangs had a series of large vent louvers where the rear side windows are on this one. The Cobras had side windows instead for increased visibility

Ah that makes sense @frater chaos...