[jhv48]

I personally have never washed my SPF in the 7 years I've owned it. I use a California duster and follow it up with meguiars detail spray.

Of course, I live in Southern California and it never gets wet or driven on dirt or gravel roads. It only gets a little dusty at times.

I did watch a shop wash a cobra one time and they basically dusted the car first then used a low pressure water hose to wet the entire car. Then they soaped it down and very carefully rinsed it off with the hose. Then they used a compressed air gun to blow water from the car and from the seams. Didn't need to be dried after that.