people say the same about my car except I rarely wash it. Silver just always looks clean. Even when its dirty it shines!
I can't tell you the last time I did a real car wash. Probably back in early April just when I did full polish/seal for the season.
I picked up a couple of nifty 36 ounce spray bottles from autogeek.net
One has FK 425 and the other a detail strength dilution of No Rinse.
Instead of dry dusting with a california swirl your paint duster, I remove dust with the No Rinse. I do the whole car with 425, paint, glass, wheels, dash.