Looks like you are located in New York ... so for the USA market, the BMW NA option BMW Assist with Bluetooth will not allow SMS text messages to be displayed on the NAV. Not sure why they "disabled this" .... however, if you dont care for Assist you could replace your BT/Assist module with the Bluetooth only ULF module (available from say http://www.bimmernav.com), then if you phone/carrier supports sending SMS over BT, then you could read SMS text messages on the NAV screen.

Hope this helps !