Thanks for the quick reply
the MS-FRD1 retains the factory microphone. I guess it must because Sync needs it. However, like you, I'm less than impressed with Sync and don't really care if I lose it and go with the Pioneer microphone. I've read where others just removed the factory one and glued in the Pioneer in the same location.
Do you have a reverse camera? If so, where did you pick up the signal?