Just a tip.
I'm in the UK and originally had my gps receiver in the left side front of my windscreen.
I had problems with reception in this position when there were overhangs. I moved it to the right side, and because we drive on the left, this positioned it nearer to the centre of the road.
In this position, the reception was significantly improved.
So for you.....if it's on the right side.......move it to the left