This is something we've been looking into and we just had a chance to go back through the code and make some changes. With your feedback we dug through the ECU code to find individual wheel speed sensors, and the averages for the front and rear wheels. We have changed the 0-60 and 1/4mi tasks to use the average rear wheel speed instead of the overall vehicle average speed. This should cut down on the early exit behavior and failed readings due to wheelspin in 1st and 2nd gears during the tests. Also, in the next major update you will now have access to monitor and log these readings for those of you that do track days or want to analyze your sessions!
-Braden @ COBB