Yes, as simple and easy as a casual driveway carwash seems on a bright Saturday morning, there are subtle pitfalls with which a careless washer could actually harm the finish, leaving scratches or stains that could require extra work to remove. Half the battle is just being aware of the potential problems. Then following through by using the right materials and techniques will make that wash as simple and easy as it should be, while also giving you the spiffy results you want. Here is a list of some basic car-washing do's and don'ts that will help you keep your vehicle's finish in prime condition.

When rinsing your vehicle, hold the hose at a low angle to the surface and let the water stream across the metal for a thorough rinse and minimal splashing. Don't wait to do a full wash if you see bird droppings, dead bugs, or other obvious contaminants building up on the paint surface. Bird droppings, in particular, have a high acidity that, if left on the paint for any length of time, can eat into the clear coat. If they reach deep enough, these scars can only be removed by sanding and repainting. Rinse this type of debris off the surface as soon as possible, using either water or an instant-detailer type of product.

Do rinse your vehicle off after a period of rainy weather if your region suffers from acid rain. The acidic chemicals in the rainwater will remain on the surface after the droplets have evaporated, leaving a mark that can permanently stain the paint

Don't wash your vehicle when the sheet metal is hot. The heat causes the soap and water to dry much faster than on a cool surface, which can make the washing process harder and possibly dull the finish. First thing in the morning is a good time to do a wash, or, if the vehicleis been parked in the shade for a while, the metal is likely to be cool enough to do it any time of the day.

Do hose off the vehicle before washing. A thorough pre-rinse will not only help cool off the sheet metal, but will also remove loose dirt, leaves, or other debris that could scratch the paint if caught under a sponge or towel. If there is packed-on mud, use a strong steady stream to break it up and rinse it off entirely.

Don't use a household detergent to wash your car. This is one of the most common mistakes. Dish soap, laundry soap, and household cleaners are often too harsh to use on a car's paint. They can strip off the protective wax coating and possibly dull the paint's finish. A dedicated carwash formula, on the other hand, is formulated with a milder soap that doesn't affect the protective coating.

Do wash the vehicle in sections. Wash and rinse one area at a time. This will help prevent the sudsy water from drying on the paint before you can rinse it off.

Don't use abrasive material on the paint. Whether washing or drying, never use a cloth or other material with a surface that can leave hairline scratches. A large sponge works well, or many professional detailers prefer to use a lamb's-wool mitt. The thick nap of the lamb's wool allows loose particles to be worked up into the wool rather than remaining on the surface. Whichever you use, apply lots of suds to help keep the paint surface well lubricated.

Do rinse out the sponge or mitt often. It's preferable to use separate buckets for suds and rinse water, which keeps dirt from getting mixed into the sudsy wash water. Squeeze the sponge/mitt out in the rinse water and then dip it into the soap bucket for a fresh batch of suds.

Don't continue to use a sponge or mitt that's been dropped onto the ground. It could instantly pick up large particles of dirt that, although you may not see them, could scratch the paint.

Do use a bug-and-tar remover to finish the job. Mild carwash formulas often aren't tough enough to remove road tar, grease, or similar residues. For this, a strong bug-and-tar remover is necessary. Since this type of grime will usually blacken whatever you use to clean it, it's advisable to use a separate cloth for this job instead of your sponge or mitt.

Don'tt use your sponge or mitt to clean the wheels and tires. Because of the brake dust and road debris that collects here, it's often the dirtiest part of the car. Again, use a separate cloth or sponge. If the residue is light, soap and water will usually clean it adequately. For more stubborn grunge, use a special wheel cleaner and brush. Be sure to use a product that's appropriate for your type of wheels. For instance, a strong acidic product formulated for mag wheels could damage the clear coat used on most modern original-equipment rims. If in doubt, look for one that's labeled safe for all wheel surfaces.

Do a final overall rinse. A fine spray is preferable for rinsing. In addition, spraying the water on at a low angle will help form a sheet of water that will better cover the contours of the body, plus will keep splashing to a minimum.

Don't allow the water droplets to dry on their own. Especially in areas with hard water, the tap water used for rinsing will have a high mineral content. When the water evaporates, it leaves the minerals on the paint, which creates noticeable water spots. Not only are these unsightly, but if left on the finish for a long time, they could eat into the paint and become difficult to remove. Even a blow dry achieved by driving around the block, isn't going to give you satisfactory results.

Do use a chamois, terry towel, or synthetic chamois to dry the vehicle. If you choose to use a terry towel, as many professional detailing shops do, have several on hand. A natural chamois works well, but requires more maintenance. It can't be stored wet and becomes stiff when dry, needing to be remoistened before use. An artificial chamois will often absorb more water, is machine washable, and some types can be stored moist without mildewing. One way to speed up the drying process is to use a soft-rubber squeegee or similar type of product to wipe most of the water off of the surface before you follow up with a chamois or towel
Affirmation :Motortrend.com