I haven't gone too terribly fast ~96mph in a 93 F-150, but 3 summers ago I was taking law enforcement classes and we had to spend 2 days doing the driving class in squad cars. We didn't have a chance to go too fast since we had a course to run and I would have killed myself going 100+ on it. But one of our tasks was to practice a straight line backing after doing a reverse slolam. My co-driver and I were trying to see how fast we could go in reverse, after all I was perfect in every test (the only one not to hit a single cone or finish too slow). We found out 40mph in reverse is the fastest the crown vics will go, but you can punch it and apparently hit a passing gear in reverse.
I pissed a lot of people of since I could do no wrong on the testing. One of them was a test where you had to drive ~40 yards, pull into a parking spot, back out, drive forward (towards the start line 40 yards and back the car into a parking spot that only had 6" clearance on either side of it. You had 45 seconds to finish this task. The instructor came over to time our practices, I of course had to go first, I screeched the tires from the start and he was telling me "go go go", so I started to do everything faster, when I was all done he said "good job...16 seconds" 20 seconds was the closest anyone else could do. I would do that weekend all over again.