Swen, I understand what you are saying now. I thought you meant that the car couldnt free-wheel when off power at all but I see your point.
Now that you opened light towards the fact that electric cars dont have manual brakes
I see how the reverse one-way operates in the electric car.
If I have this correct then when you use a speedo with reverse the car reverses effectively using 2nd gear. Bound to be sore on the batteries.