Why poor washing does more damage than the road does
Almost all the fine scratching and swirl marks you see on a dark car under low sun were put there during washing, not by driving. Rotating brushes at drive-through washes, a sponge that has been dropped, one mitt used from the wheels upwards, or drying with a towel over a surface that is not properly clean — each drags grit across the lacquer. It is cumulative and it is why a three-year-old car can look duller than a ten-year-old one that has been washed properly. Correct method (pre-rinse, contact-free foam, clean mitt, two buckets, safe drying) removes the largest single cause of paint deterioration in normal ownership.