I have the Nokia Bluetooth kit (ck100 I think) linked to standard stereo - very discreet, works a treat - even supports music streaming and Siri/ navigation through iPhone 4S. Says "goodbye" when u exit the vehicle - just the job.
Pair it with a Tetrex x way holder - magnetic so no ugly holders stuck on windscreen.
Cheap way to get all nav/ hands free/music streaming if have an iPhone.
It will do till I save enough pennies for the RNS510 - shell out nearly a grand to get the exact same features as I already have!.... But they just look soooo good!!!!