Ken did you ever get this sorted? I have the Maestro RR unit in my 2010 and I'm pretty sure I spliced into the blue wire with an orange stripe. I ended up following the SYNC wires over to where they come down behind the dash kit and got at the wires from there because it was too awkward for me to get at the wires behind the glove box.
2010 Black GT. Appearance mods only so far. SS center fog grille, DG Customs side and window scoops, SLP Loudmouth axle backs, Roush center console button, Roush white shift knob and boot, Metra touch screen dash kit w/ Kenwood/iDatalink NAV setup to retain SYNC.
NOTE: OEM grille, mufflers, and 401A shift knob w/boot are for sale if interested. PM me an offer.