I just thought about this when I seen a player speed hacking...
We should add a speedometer to the game.
The second part of this suggestion is to add a message which would be sent to admins if a player is driving at a speed which could not be reached without using a hack..
For example player X,who using a speed hack while driving,his speedometer digits would be high for example let's say he is speed hacking,and his speedo says 4000KM/H
a message similar to this could appear to the admins..
Player X(whatever ID) is traveling at 4000KM/H