That old Box Train vehicle has a SpeedCheck script that has a brick per second speedometer, you could use that for various vehicles
I gave it a shot, i can't seem to get it to work, but it also returns no errors in the console
package VehicleSpeedometer
{
function VehicleSpeedometer(%data, %obj)
{
if(!isObject(%obj))
return;
%vehicle = %obj;
%speed = vectorLen(%obj.getVelocity());
if(!%vehicle.oldSpeed)
%vehicle.oldSpeed = %speed;
if(%speed < 0)
%speed = 0;
%vehicle.oldSpeed = %speed;
commandtoclient(%vehicle.getControllingClient(),'bottomprint', mFloor(%speed *2) @"<color:FFFF00>BPS", 1);
schedule(500,0,"VehicleSpeedometer",%data,%obj);
}
};
activatePackage(VehicleSpeedometer);
function vehicle::onadd(%data, %obj)
{
parent::onadd(%data,%obj);
VehicleSpeedometer(%data, %obj);
}
I've also tried putting the function in the package, same results