HOTTROD, In order for your bra not to defeat its purpose, make sure the surface it will cover is completely cleaned and waxed before putting it on. Also, make sure that the bra is applied correctly, so it is not loose. any rubbing or slapping from a loose bra will mar your finish. I would also reccomend that you remove it when you wash, and always apply wax to that area, even if you aren't waxing your whole car. Bras can trap moisture, making black mold spores, which are ugly, and if left too long, can be difficult to remove.
Craig, I agree with you on the newspaper thing. It is an excellent "trick". However, I usually use just plain water with a terry towel, unless the windows are very dirty. Works just as well as spray stuff and paper towels, and costs less!! remember to buff windows with a dry cloth also when done to eliminate those streaks you see when you windows get fogged up. I have used the foam spray cleaner by Spray-away, that stuff is a saint. No matter how you apply or remove it, it dosen't streak, but it costs $.