Dunno which model it was. I think it was a Ford, possibly a Fiesta, a C-MAX, a Fusion, a Galaxy or a Kuga. Had the black main color, the white doors, the "POLICE" markings and what appeared to be the "To punish and enslave" markings. I only saw the car in passing by from a distance so forgive me for not being able to tell what model it was. I know for sure it didn't look anything like a Mustang, though. Unfortunately I had no camera with me. That thing looked bizarre.
I know how that feels. There's a Mustang near where I used to have an apartment that's painted identical to Alt Wheeljack. And every time I happen to see it in the area, I can never get my camera phone ready to snap a pic in time before it's already left me in the dust.
There's a place right near me selling a yellow volkswagon bug for $1500. I want to buy it so bad. Supposedly bugs are easy to maintenance, and I know a mechanic who had one of his own he worked on. I'd love to get it and put some autobot symbols on it. haha