The greatest single cost in car ownership is depreciation. Basically, the second you drive your car off a dealer lot, it loses value and will continue to do so until you either decide to sell it or it stops working.

By taking proper care of your car, keeping it looking good and running smoothly, you can ensure that it fetches as much money as possible when it comes time to sell or trade in. Following these five simple steps will work wonders in maintaining your vehicle's value.

1. Keep your service records

Service records are the best way for you to show a potential buyer you've taken care of the car's mechanical components. Without service records, it's difficult to prove that you've changed the oil on time and that you've met factory service requirements. Most sellers will claim they cared for a vehicle properly, but actual records can give you an advantage. Records can be computerized or they can be put into a booklet in the car's glove box. If your dealer or mechanic uses a computerized system, make sure to get printouts of all maintenance performed.

2. Avoid dents and scratches

Dents and scratches can happen when you're parking, when you open your door or even when you place an object on your car. Cosmetic imperfections are expensive to repair, and can be a huge turn-off to potential buyers. Luckily, by washing your car regularly and taking extra care to avoid contact with other objects, you can keep your car looking like the day it left the factory.

3. Keep the interior clean

The appearance and smell of the interior can also impact the attractiveness of your car to a potential buyer. Most people wouldn't want to buy a car with foul odors or food stains. To keep your interior fresh, avoid smoking, eating and drinking in your car. If you do eat or drink, throw away the empty food and beverage containers immediately, and clean spills with the proper cleaning solutions.

4. Don't curb your wheels

Parallel parking can be a risky proposition if your car has alloy wheels. If you get too close to the curb, the edges of the wheels can get scratched or bent. Many buyers of higher-end vehicles pay close attention to the condition of the wheels, and will walk away if damage is readily visible. While it's best to avoid damaging your wheels in the first place, professional wheel repair shops can refinish damaged wheels for much less than the replacement cost.

5. Polish faded headlights

After years of sun exposure, your car's plastic headlight lenses will fade and turn yellow. While the rest of your car might look terrific, the yellow headlights will reveal the vehicle's true age. Luckily, faded headlights can be polished by most auto detailers. Polishing the headlight lenses doesn't take long, and shouldn't be very expensive. Buyers will appreciate the difference when they compare your car to other cars of the same age.

Stan Markuze is the founder of PartMyRide.com.