Yep. The question is still wide open.
Apparently PSP was using Mustangs in the 80's (as shown above). The question now is if they were using base Mustangs or SSP's.
I now for fact I saw one around 84-85. But now I can't remember if it was a notch or a hatch.
When I moved in to the right lane to let it pass, I think I was to shocked to see a Trooper driving if first, and the fact it was a Mustang second. That and that it had a red light stuck to the front of the dash.