Hello,
welcome
I've found this:
Washing
by David W. Bynon
Copyright©, 1999-2002, Autopia Car Care -- All Rights Reserved
Washing is the process of removing loose dirt and road film on the top of your car's paint surfaces. A good car wash solution provides lubrication to prevent scratching and conditioners to maintain the shine.
Washing can be a double-edge sword, though, as even the mildest soaps can remove waxes and sealants from your car's paint, allowing oxidation to begin. Detergents are very harsh and will dull your car's finish if used frequently.
For years, BMW, Jaguar, Mercedes-Benz, Ferrari and most other fine automobile makers recommended using only pure water to wash your car. When you find a shampoo you like, be sure to follow the manufacturer's recommendations for usage. Using too much shampoo will cause streaking and reduces the longevity of your wax.
Here are some tips to make washing easier:
1. Wash the wheels first!
2. Make sure your car is cool and work in the shade, if possible. A hot surface causes the wash and rinse water to evaporate too quickly, increasing the likelihood of water spotting. One trick is to park on a slight incline. This allows rinse water to run off moldings, trim, and recessed areas better. Start by thoroughly wetting the car's finish with a medium spray of water to remove loose grit and surface dirt.
3. Use a car wash shampoo specifically formulated for automotive use. Look for a shampoo containing surface conditioners and natural oils. These oils act as a lubricant. Sand and abrasive grit slide off in the rinse water without scratching the surface. These shampoos cost a little more but are worth every penny if you own a dark color car. Follow the shampoo manufacturer's directions for the proper mix ratio. Using too much shampoo is wasteful and may leave a filmy residue on the surface.
4. I prefer a natural (not synthetic) sea sponge, cotton chenille pad, or sheepskin wash mitt for washing. These tools have a large number of fine filaments that draw dirt and grime away from the surface being cleaned into their internal structure. Synthetic (flat sided) sponges and wash clothes can trap dirt, grit, and grime on the surface which can scratch your car's paint. If you use a natural sea sponge, use the outer "soft" side for washing, not the harder "cut" side, and always rinse new sponges thoroughly to remove any remaining sand or shell particles. 100% cotton chenille wash mitts and pads are also excellent as they hold lots of soapy water and are gentle to your paint.
5. Start washing from the top down and rinse the car often. Frequent rinsing is especially important if you are using a wash containing natural oils. While these oils cushion the paint and minimize abrasion they are heavier than water and can leave a film if allowed to set on the car. I use a final rinse of free flowing water (nozzle off the hose) allowing the water to sheet off the car.
All products mentioned in this article are available from Classic Motoring Accessories and are used at the buyer's own risk. Autopia Car Care is not affiliated with and does not represent Classic Motoring Accessories or the manufacturers of the products mentioned. Other fine sources of car care products include Car Care Online, Griot's Garage and Top of the Line.
Hope this helps,
It's my washing technique , and it works for me
I allso use 2 buckets to wash : one with the soap-water and an other with only water in it : dip your sponge (or wash mitt or,...)in the soapy water , wash , but instead of putting the sponge (mitt,...) back in the soap-water , rince it in the water-only bucket , then back to the the soap , etc :
this prevents dirt getting in to your soap-water , thus preventing dirt crawling back in your sponge(mitt,...) thus preventing swirls.
Greetings ,
Christiaan