i responded to you on the sprint forums..
ive a sprint one max and i have no issues. it behaves just as the htc one did.
what phone did you have prior? did it not have any issues?
do you have an aftermarket system or factory?
what apps are you trying to stream from?
how about making phone calls, can you at least do that?
or does the phone not even show the relationship in the BT page with your car and the one max?