I using a Plantronics Voyager 9(something or other) headset (it shows up in my BT menu as 9xxPlantronics,) company car is a Ford Fusion with Sync, and my Jeep has a JVC KD-AHD75BT aftermarket head unit. My MoPho will sometimes auto-connect with the JVC, but never with either of the other devices. With all three devices, I also have paired a Samsung Rugby (my employer-provided phone - I hate it, but apparently carrying it around with me and answering it is one of my conditions for employment, and I *have* to have that one paired, because the internal speaker in that thing is awful, I can barely hear someone talking to me on the other end if I'm in a quiet room with my finger stuffed in my other ear and I am concentrating really hard. Ironically, despite everything about that phone sucking arse, it auto-pairs with all my devices and everything in that respect works seamlessly, except I have to reboot it maybe once a week because it'll start dropping BT connection when it's on the charger if I don't (and it's on the charger all the time...)
Kolio, I had high hopes for your suggestion, because I never thought to do a long press to open a context menu, but I don't have an auto-connect option. I just tried it and the options are "Disconnect," "Disconnect & unpair," and "Options..." if I hit options my options are "Connect" and "Phone" (both checkboxes)
AFAIK my MoPho is unmodified other than the 64GB SD card I threw in it to carry my mp3s around, and it's got all the updates that Sprint has seen fit to pipe down to it.
Any ideas?