There's a great product for cleaning cars with out water... it's called Dri-wash. I've been using it for years on my "90 300ZX and my 528. I keep both in a garage all year, but in winter the bimmer is the only one that's driven on a daily basis. Depending on when any salt is laid down... I keep my car washed in a no-touch auto wash, with spot rinse... then put it in the garage and go over it with the Dri-wash... the car looks mint every time! Dri-wash has a website @ www.Dri-wash.com. They also have a 1-800 number which you can get from information. The stuffs not cheap, but it does a great job of cleaning... polishing ... and protecting the car all year!