The main problem I think is the seasons...spring and summer. The pollen is everywhere, and when it rains, the pollen collects on the outer edge of the rain drops on the car and you are left with water spots with hints of yellow. Maybe in the fall and winter when the pollen dies down, I won't notice it so much.
This past weekend when I washed my car, it rained the next day. I hosed down the car really good and sprayed Meguiar's Quick Detailer and wiped down the car. That seemed to help. Im not going out every day this week and wiping down my car just for a few hours of shininess every day.