I have a 2005 Audi S4 without Nav. This is the early model from 2005 (I think there was a redesign later in the year). Mine has no controls on the steering wheel for stereo or bluetooth. I want to add bluetooth capability (like a Parrot 3000 EVOLUTION). Does anyone have any advice on this? Which bluetooth unit to buy? Is there a way to upgrade the steering wheel as well so it is totally integrated? Thanks!