Correct
Before & After shot during a single stage paint correction detail on a Mercedes GL.
There are many different types of damage to automotive surfaces. Wash marring & swirl marks (thousands of scratches in every direction giving the illusion of a swirl pattern), random isolated deep scratches (RIDS), oxidisation/paint fading due to UV exposure, chemical etching, bug acid etching, bird mess etching, water spot mineral deposits to name but a few. Although not all damage can be rectified with detailing the majority can in fact be safely removed to restore the finish to a mirror-like state.
Protect
Impressive water repellent properties from a high quality synthetic sealant on a Honda Civic Type-R.
Everything degrades with time. When it comes to car care if a surface is left unprotected it will degrade more rapidly. This is due to exposure to things such as UV radiation, bird droppings, bug splatter, acid rain, dust, pollen and general dirt and debris. When you combine these with poor contact with the vehicle while washing and drying it becomes very apparent how damage can occur. Surfaces which are unprotected also allow contamination to build up quicker and bond more firmly. Bonded contamination requires more force to remove which may result in either chemical or mechanical damage. This is why it is so important to keep your vehicle protected and care for it correctly.
Maintain
Pre-wash stage on a Porsche Boxster Spyder prior to a safe wash.
Scratches (often referred to as swirl marks) are inevitable and will accumulate over time regardless of how you wash your vehicle. If you're making contact with the paint, no matter how safe you think it is, you are scratching. All that can be done in terms of maintaining a brilliant finish is to carry out each cleaning step correctly in order to reduce the rate at which such damage is inflicted. Proper education is crucial when looking after your vehicle if you want it to remain in it's current appearance. Prevention is always better than cure.