Yes, the Flex has the Sync system. It has not always played nicely with my iPhone, being a MS product. But the Bluetooth function works well with the Bluetooth on the Iphone 4S for other uses.
Bluetooth may not be fully intergrated with the Maps App yert, but when Bluetooth is turned on on the phone and you press the "start" button for turn by turn directions, a Bluetooth button pops up in the Maps app, offering the choice of play over Bluetooth or play ovewr iPhone, that's similar to the sequence for phone calls on the iPhone when Bluetooth is engaged. Unfortunately, with Maps, the voice directions do not play with Bluth Tooth turned on no matter if you select play over phone or play over Blue Tooth. If I turen Blutretooth off on the phone, so that it is not available for any function, the voice turn by turn directions work fine over the phone while in the car.
So, it could be something specific to the Ford Sync system ort it could be specific to the Maps app. I'm interested in learning if other have run into this and what a solution might be, thanks.