There was a thread earlier about an Alpine NAV unit that allowed for cell phone interface. The question was posed if the MDX unit also could do the same. Not sure it was resolved but you might do a search.
The auto makers are really pushing congress for a total ban of cell phones in cars in the US. They want it limited to in car, voice activated units. Geez, I wonder why?
Anyway look for your wireless carrier to offer voice activated dialing in the near future. Many companies are doing trials this year and expect major rollouts later. You would still have to press one key, a pre programed key with an 800 number, to activiate the dialer but after that it would be hands free. Should work with pre programmed numbers as well as a speech to text dialer for un programmed numbers.
Chris