i have seen a m nav 650 for sale as a sat nav but all the details i can find seem to relate to it being a message system combined with sat nav, does it work as stand alone sat nav or only of use when combined with the Qube thing that is fitted in the car, most importantly can i power it directly as there is a socket for a power lead but no lead, what voltage would be needed to be input to power it. i can be contacted on bryanandelaine@gmail.com