I got my P85 with tech package about 3 weeks ago and have just over 800 miles. Today I used the nav system to drive to a rural area with poor cell / 3G coverage. The nav worked flawlessly on the way down. On my return trip I tried to speak my destination but got the message that there was no connectivity so I typed the destination address into the nav display. The nav started speaking and displaying turn by turn directions. After 2 miles it stopped navigating. I hadn't hit cancel. My passenger re-entered the address and the nav system worked for about 2 miles. This happened a total of 5 times until I decided to use my smartphone instead. The navigation is supposed to work with the tech package even when there is no cell / 3G signal. Any ideas?