iPhone cheps: Found on a Murcan forum a thread showing that iOS6 appears to now enable the SMS function on Bluetooth-connected cars. You may have to delete the current 'pairing', and re-pair, but once done, click on the blue arrow to the right of 'MB Bluetooth' (or whatever your car is 'called') on the phone (once in the settings>>bluetooth menu), and slide to enable notifications. I did this and the SMS in the telephone screen is now not greyed-out.
Haven't tried it out yet, but looks promising :)
Haven't tried it out yet, but looks promising :)