So on my way home from work today I tried the only spot I hadn't tried before, the slot for the phone between the two cup holders in the front, and Waze worked flawlessly. Not one second of dropped GPS signal in 90 minutes. Maybe the upright position of the phone situates the GPS antenna to pick up signal thru the side windows. For those having GPS issues it might be worth a try, although not ideal if you carry beverage cups (I don't). Hopefully it'll continue working for me in the coming days.
HSE | Caesium Blue/Siena Tan | 20" Style 5068 wheels | Received 01/09/2019