Properly preparing a used car before a sale or trade in can make a dramatic difference in the vehicles curb appeal and perceived value, according to Consumer Reports car experts in the organization’s latest of New Car Buying Guide 2006-2007.

When it comes to prepping your used car to sell or trade in, Consumer Reports experts note that you can do a lot of the work yourself. You may need to enlist professionals for some important repairs, but the more elbow grease you invest, the less you will need to pay someone else to do it. Here are some of the highlights on how to get the best results:

• Spiff up the exterior – CR highly recommends the vehicle be given a thorough cleaning with car-wash detergent and water. Scrub the wheels thoroughly and remove any road film. Once everything is dry, apply a tire dressing to give the rubber a new look. If the paint is in good condition, a coat of wax may be all it needs. If it’s the original factory finish, it likely has a clear coat outer layer. So, make sure the wax used is “safe for clear coats.” Small scratches and chips can be fixed with touch-up paint, available in model- matching colors from the dealership. Fine surface scratches in the paint can be professionally buffed. It will greatly improve the car’s appearance but typically costs between $100 and $200.

• Remove small dents – Having a body shop fix dents can be costly. If there is no paint damage, it is possible to use a service called paintless dent repair. They used special tools to massage out small dents from the inside. Typical costs range from about $50 to $150 per dent. Some do-it-yourself dent-removal kits exist. They cost about $20 to $30. Two kits that Consumer Reports tested were Ding King and DentOut. They worked equally well, but results were not perfect. Generally, the more experience you have, the better the results.

• Fix window-glass defects – “Star” and “bull’s eye” glass damage from flying stones can be filled by an auto-glass service so they are less noticeable. The cost to fix small glass dings will run about $50 to $60. For large cracks, the entire windshield must be replaced. Owners should consult their insurance policy first. If they have paid for the glass premium, the replacement is free, except for a possible deduction.

• Clean the interior thoroughly – Remove all personal clutter from the vehicle. Check under the seats for lost items. Special cleaners exist for upholstery, vinyl, and leather. For hard plastics surfaces, use any good all-purpose cleaner. To get rid of interior odor, clean fabrics with a pet-spot cleaner or other odor fighting products. To remove stale odors from the ventilation ducts, spray odor eliminator into the air intake; this is usually located at the base of the windshield. Then run the air conditioner full blast for at least 10 minutes.

• Clean the engine compartment – A clean engine gives the impression that the mechanicals have been well maintained. Use an old tooth brush dipped in a mixture of water and baking soda to clean any corrosion or white powder off the battery connections. Then coat the terminals with battery terminal grease. Soap and water can be used to scrub down the external engine parts, but an aerosol engine degreaser may work better. Do not get electrical connections wet. Loosen dirt and rust from iron and steel parts with a soft bristle brass wire brush and soft abrasive cleaners.

More tips are available in the Consumer Reports New Car Buying Guide 2006-2007 ($9.99 U.S./$12.99 Canada) which is sold on magazine racks and bookshelves.