are you asking about the history of all vehicles and their reverse speed or current production? Because all current production vehicles have a reverse speed regulator.
Theoretically, electric vehicles could go very fast. But they have speed regulators also.
Any production cars that follow the rules set in the OP, past or present
On a dynamometer or human driven?
The Saab 93 has a top speed of 72mph, assuming the aerodynamics going backwards don’t limit that. If you don’t want any tricks with spinning a 2 stroke backwards you’ll be hard pressed to beat the C7 mentioned up thread. Corvette gearing is nuts.
This is almost certainly bunk. I plugged everything I could find on the 9-5 aero into a gearing calculator and came up with 42mph at 7k rpm for the automatic. 38mph for the manual.
The ratios I found might be off a big depending on specifics but 70mph doesn’t seem realistic.
Do any of the vehicles being thrown about not have a speed regulator?
I missed your post about the crown vic hitting 60mph in reverse. Based on what I’m seeing for 4R70W transmission ratios in 95, the P71 would have had a theoretical top speed in reverse of about 78 mph, and the civilian model with its more pedestrian final drive a whopping 93mph!
I’ve never had a car that has a governor specific for reverse. The crown vic is limited to 110 and the P71 to 127, but my google-fu is coming up blank for a second governor just for R.
I think the crown vic might be the champion here.
The vehicles that govern how fast they can go in reverse likely aren’t getting mentioned in this thread in the first place.
We’re also talking about both current production, and cars from 20, 40, or even 60 years ago. Speed regulators are rather recent inventions on that time scale.