Sprucing up your car with a used-car dealer's finesse

Did you ever wonder how used-car dealers get their cars to look so new? The magic is called ''detailing,'' the art of touching up a car to hide minor damage and imperfections from all but the most discerning eye.

Detailing isn't hard to do, either. The fact is, you can detail your own vehicle so it looks more valuable than ever around town or on the trading block. Here are the steps, the tools, and the know-how that will do the trick:

1. Wash the car thoroughly with detergent and water, taking account of all the tiny nicks and dings that have accumulated from kicked-up and thrown stones as well as parking lot abuse. (Heavier damage, such as dents and scrapes, cannot be repaired by detailing. For a good-quality job, have a professional do the bodywork and painting before you do Step 3.)

2. Spot-in paint chips with color-matching touch-up paint (designated numerically on the cowl tag of the car's firewall) and a small modeler's brush, toothpick, or the torn end of a paper matchstick. Dab the paint lightly into the chip several times until it fills in the damaged area. When it's dry, carefully sand the painted areas smooth with No. 600 wet or dry sandpaper.

3. With the aid of a medium cutting compound, buff the car to remove oxidized paint, ground-in dirt, and small scratches which dull the car's finish. To do a good job and avoid unnecessary damage to your car, exercise great care in the buffing process:

* Tape off and avoid buffing all the sharp edges at body seams, such as where the hood meets the fenders, and areas where the sheet metal makes a sharp bend, such as the fenders. This will prevent you from buffing through the top color coat. These areas can be finished by hand later.

* Do not exceed a buffing speed of 2,000 r.p.m.

* Buff in the proper direction. Always buff across and off the top of edges rather than against them. Work from the middle of a flat surface out to the edges, and never buff too long in one spot. Keep the pad moving so you do not burn the paint.

* In the case of a multi-toned car, buff the light colors first.

* Keep the work surface moist with water applied from a small spray bottle.

* Use a pad with a 11/2-inch pile and keep it moist so it won't become gummy. Also dry the pad frequently by running the buffer upside down and stroking the pad with a putty knife or comblike device. Protect your eyes when doing this.

4. Polish your car with a paste wax or polymer-based sealant. For an easier, more effective job, work in the shade, use cotton T-shirts or even cloth baby diapers for rags, and change them frequently so they don't load up with wax.

It doesn't hurt to be stingy when applying wax around doorjambs and hood and deck-lid openings. Dried wax is hard to remove from these areas, especially if it gets on rubber or plastic surfaces, and what you leave behind can really detract from your car's appearance.

A trick that will rid the finish of excessive wax is sprinkling cornstarch over the surface while the wax is drying. Besides allowing you to rub the wax off easily, the cornstarch will create a high luster.

A toothbrush or small stiff-bristled modeler's brush are excellent for removing all the wax that accumulates in nooks and crannies around emblems and trimwork.

5. Polish the metal brightwork. Regular chrome parts should be polished with a commercial chrome polish. If your chrome shows a lot of water marks, it may require many applications over several weeks before the luster is fully restored.

Just the opposite holds true for anything that has flash chrome coatings, such as some types of plastic body side moldings. These should be treated with kid gloves so as to avoid ruining their finish. Going over them with a damp rag or using a very mild cleaner is enough to bring out their beauty.

Should you own an older car with a lot of stainless-steel trim, consider using one of the special metal polishes on the market today that are designed to protect as well as beautify surfaces.

Detailing your trim first with 0000-grade fine steel wool will also help eliminate any surface rust and pitting.

6. Depending on the type of car you have, remove what pieces of grille as well as headlight and taillight trim you can for further detailing. Many cars have portions of this trim that are painted. If it's too far gone, you can clean it up with steel wool and repaint it for a nice new look.

7. Clean the car's glass. This is easier said than done, however, especially if the windows are water-spotted. However, you can cut the job and the film by using an ammonia-based cleaner along with some 0000 steel wool.

Another time-honored favorite is to polish the surface with newspaper.

Voila! Your car is worth more money.