After watching Ben Goodwin's videos of testing the Roadster 2.5 on icy roads, I found myself wondering: If Traction Control and/or the wheels spin for any reason, then how accurate is the tachometer? I assume that the speedometer is driven by the front wheels, so spinning the rears will not make the speed shoot up to an inaccurate reading. However, if the speed remains accurate when spinning the wheels then the tachometer surely does not. You can hear the motor revs as they increase, but there's no real readout. I have no doubt that the PEM will protect the motor from exceeding its maximum safe rpm, but it seems somewhat awkward to have a tach which doesn't reflect the actual rpm under all conditions. Any thoughts?