I had a similar situation in my Mustang before I got my Challenger. Pulled away from an on ramp and ran it up very quicky through the gears but then let off at a shade above the legal limit. I was careful not to squeal the tires because I saw what I thought might be an unmarked car behind me.

At the next intersection, he flashed his headlights (not the reds and blues) then got out and ran up to me in my car. I was thinking WTF before he got to my window and his first words were nice car. Then he asked me what I had under the hood and said he was off duty and just messing with me. He let me go with a pat on the shoulder.

Meanwhile, I was sweating bullits...