I see that on numerous aftermarket radios and navigation systems, they offer a "bluetooth" adaptor kit for around $200. Has anyone found anything like this for Cadillac vehicles? I know there are numerous aftermarket systems that can be installed but who wants another LCD screen added somewhere on the dash? I get frustrated when I see all the new vehicles with built-in bluetooth and their phones work through the nav. screen along with their address books. And, these are not high end cars that have it. Please let me know if someone has found something.