Usually when I use a receiver in the car, I leave it on the strap, however yesterday, I was using a Voice Sense with Sense Nav and did have the receiver up against the car window. It was super neat because Sense Nav overwrote the route that had been automatically programmed into it before I went to the cell phone store. With the Holux m1000, I have had a reading of 8 satellites clear across the living room from the patio door. Mary Ellen Earls