[Nuttyman54]

First thought: This is going to be impossible to make a module drive straight. A very small speed differential between the two wheels will make this turn for any reasonable driving speed gearing.

Second thought: Making a module point in the desired direction requires running the differential for a short (possibly VERY short, depending on the gearing) period of time and then stopping. This seems like it would be highly inaccurate.

Third thought: Trying to make 3 or 4 modules all point in roughly the same direction this way without mechanically connecting them seems impossible, especially given the update rates of our control system. To make it controllable for steering, you would need to gear way too low to be usable as a drivetrain.

This was a good thought exercise.