Txlxs

I have a 2006 lexus IS 350 that I adopted from my wife to use for business. A couple of yrs ago I installed a Parrott BT in the car. It works fine, but when streaming or on a call, you have to turn the radio up so loud that it scares the hell out of you when the call is dropped. The volume on the Parrott unit is up all the way and it still doesnt make a difference. I like the car and its paid off. But I use the BT a lot. I really dont want to get rid of it because of this. Is anyone else having this problem? Is there a better aftermarket BT unit? Im not concerned with running the iphone from the car controls. Just want to be able to stream music and make calls. Thanks for any advice.