windshield mount

I have the iphone 7 plus with the juice pack and am presently using a windshield mount but have been noticing that the iphone will pop out of the mount due to the thickness of the juice pack. It really doesn't seem to me to be that thick but the sides of the iphone are very slick due to that juice pack. I am looking for another mount that I can attach to my windshield so that I can view my screen as I am driving. It works better when the phone is in the panoramic view due to it picking up on my radar detectors app. can anybody give me some good advice as to what to purchase here that is dependable and will work out? Thanks. Also it does get fairly hot here where I live during the summer months bur the heat hasn't really affected the sticky cups ability to stay stuck to the windshield on my present unit.