If you have a camera without any kind of viewfinder (like my S4), here is a solution for the problem of screen reflections on a very bright day.
The next time you finish off a kitchen roll, take the empty cardboard tube and put it in the car - that way, when you find yourself is a fantastic location, trying to take panoramic shots, you simply put one end on the screen and the other end against your eye. It really works - I promise you!
You may look like a maveric using a cardboard tube, but you'll get the shot you wanted! :-)