ZH 
EN 
Paint is the most vulnerable part of a car. Even a light brush in traffic leaves a mark, and a stiff branch will scratch it. And without care the paint oxidises and fades even with no outside damage at all.
1. Car covers
Most owners do not realise a cover can damage paint, though its whole purpose is protection from sun, rain and debris. In wind, fine grit trapped in the relatively sealed space under the cover rubs against the paint and leaves heavy scratching.
2. Laundry powder and dishwashing liquid
Many owners think any detergent that cleans is fine. That is wrong: detergents differ in composition, and laundry powder is alkaline, which is very damaging to paint.
Use a purpose-made car shampoo instead: it cleans while protecting the paint.
3. Wiping a dry, dusty car
Dragging a cloth over dust grinds the grit into the paint. Rinse first, then wash.