DETROIT » If your aging car looks shabby — blemished by a scratched paint job or dirty upholstery — you’re not alone. People are keeping their cars longer as they wait for the economy and jobs market to improve.

The average age of a household’s newest car is just over five years, which is nine months older than in early 2008. An older car doesn’t have to look grungy, though. Here are tips for making your car look almost new again.

Shine up the paint: Embarrassed by nicks and scratches on your car? Buy some touchup paint from a dealer or auto parts store. Wash the car thoroughly, then paint over the nicks. Once the paint dries, coat your car with high-quality wax or polymer finish to bring back the shine.

To bring back even more shine, buy a clay bar. It’s a little block of clay that professional detailing shops use to remove contaminants, such as tar or sap, that are stuck to the car’s paint. You can buy clay bars on the Internet or at auto supply stores. Coat your car with a special lubricant or car wash liquid, mold the clay bar into a little pancake then gently rub the car’s surface with the clay.

"Clay barring is like exfoliating your skin," says Matt Lifter, owner of Motor City AutoSpa, a detailing shop in Royal Oak, Mich., near Detroit.

Wax, a clay bar and car wash liquid cost around $50 all together. Touchup paint costs around $10. Or you can have a professional treat your car’s surface with a high-speed polisher, a five-hour job for which Lifter charges $149.

Wheel cared for: Do the wheels on your older car look grimy instead of shiny? Your brakes might be at fault.

Most brake pads are made of metal compounds that give off dust when you stop your car. The dust can stain your wheels and rims. You can remove the stains with liquid wheel cleaner and an old toothbrush.

There are good brands of wheel cleaner available for around $10. Wheel cleaning is also available at detailing shops.

Scrub the interior: If you spend a lot of time on the road, then your car becomes a second living room. That means a lot of crumbs and grime can build up on upholstery and the dashboard, especially in older cars.

Rent an air compressor for around $20, or buy one for $180 or more, to blow dirt out of the car’s crevices. Then vacuum it up.

For $20, rent a steam cleaner with a wand that will work on car upholstery and carpeting. Apply a high-quality detergent, which costs around $10 to $20.