I wanted to have bluetooth capability in my 2007 Avalanche so I could have hands free cell phone and stream my music without breaking the bank . I found a Belkin AirCast Auto Handsfree unit on Amazon. It connects through the AUX input and so far is working great. Sound quality on the phone is excellent as well as streaming music from my Iphone. It has some limitations. It does not automatically sync with the phone , you must press the Call/Play button when you get into the vehicle and if you were listening to the radio you would have to change the source to the AUX input in order to hear the caller. Since I usually am listening to music from my Iphone it is not an issue for me and I don't see it as a big issue if you were listening to the radio or the CD
For the price and capability I think it is hard to beat.
Link to Belkin Product Page below.http://www.belkin.com/IWCatProductPage.process?Product_Id=530115