Not sure if this is helpful to you, I have found that I can get a lock relatively quickly if the vehicle is facing south when I initialize the Map program, or if I am standing outside facing south. I do get lock times in about 15-30 seconds. It can take minutes if the car does not have a good view of the southern sky. Not sure why it works, just an observation I made while playing around. Once it is locked, I have had no problems losing lock, even driving thru town with all building or in forested areas.