What we would need first is a standardized method of determining what top speed is.

Land speed records are measured over a measured distance(a mile?). Of course they get up to speed before reaching the accurately placed measuring devices,most likley placed by a surveyor.

Drag Racing used to measure top speed over a 120' with two light beams. A beam placed at 60' past the first was the win-loss light. Now they do it with two 30' apart, the first starts the mph clock and the second stops it and is the win-loss light.

In both cases average speed through a measured distance is used.

Soooo. What distance shall we use? Hummmmm.