You can still use the MPGuino on OBDII cars as long as they have fuel injectors. MPGuino has nothing to do with the OBD system unlike the SG or UG, which rely on the OBD system to collect data.
Here is where you can buy a MPguino:
MPGuino trip computer - MPGuino
He is actually on Ecomodder under the username meelis11 if you want to contact him directly.