I went to visit my friend who has an electronics based business and he helped me design and construct an on-board signal processor for the MPGuino. We used one side of a dual Opamp IC to create a comparator for the VSS input. We first took the O'scope out for a drive and saw that at low speeds the signal from the VSS was as little as 250mv. We then designed a simple comparator with a hysteresis loop for clean transitions state to state. Unfortunately the only op amps my friend had were surface mount so I got to do some soldering under the microscope (usually reading glasses are enough
). Initial in vehicle testing showed the need for a zener voltage clamp on the input. that plus some fine tuning of the hysteresis resistor value resulted in perfect VSS functionality! Speed is very smooth all the way down to .5 mph. Instant MPG is steadier now too. I have no doubt that the DRAC module could be made to work, but this little board glued right on to my Arduino and works great! I will publish the schematic as soon as I get some freeware for drawing them. Thanks again for your help.