I know that there are a lot of tricks out there using just water - using newspaper, etc. but I prefer using an actual glass cleaner type of product to clean the windows. Any favorites out there? Yesterday was a beautiful day to clean the car for the first time, and I used the Martha Stewart Glass Cleaner, followed the instructions, and it didn't leave streaks, but it seemed to do nothing for the water spots that were on the back windows (in particular the lower one), so I rewashed those windows with the turtle wax car wash detergent, dried them and tried a spray glass cleaner and that worked a bit better, but didn't clear them completely. Is there a better product out there?