You need to look around in the NAV settings and turn off all the notifications. It's likely the speed warning as was mentioned earlier.
I was getting a "cannot find satellite" warning message every few minutes. I've since turned all NAV volume setting to zero. That fixed that problem.
I think FR should just put a plain old stereo in these things with USB and BT.
Offer the NAV system as an upgrade. You can't even see the screen half the time due to glare and the bad angle.
My Tom Tom or Garmin GPS gets the nod when I need a GPS.