http://www.gtacarkits.com/product/lex...
How to install and use Pure Bluetooth Kit for Lexus GS 2006, 2007, 2008, 2009, 2010 and 2011 model years.
The stock bluetooth in Lexus GS only can place and receive calls but cannot stream music. GTA Car Kits has both hands-free calling and wireless music streaming functionality. Limitation: You cannot use stock and GTA Car Kits Bluetooth at the same time.

Using this kit you can take/place hands free calls and wirelessly stream audio. You can also use car controls to switch calls and answer/hang up the phone. This kit supports any bluetooth mobile phones including but not limited to iPhone, Samsung Galaxy, HTC, Blackberry, Windows Mobile.