Car enthusiasts often spend hours on cleaning, polishing and waxing their cars. For some, it's a weekly ritual to park the car in the driveway and spend a few hours around their cars with a bucket of soapy water, a hose and a container of wax. Car bumpers were once made of chrome, and car owner would spend hours polishing and shining them. Today, most car manufacturers install plastic bumpers on new cars, which involves different cleaning techniques.
Wash the bumper with a commercial car-washing product. (You can purchase the commercial car-washing products at an auto-supply store or an auto centre.) Follow the directions given on the product's bottle. Scrub the plastic car bumper with a soft bristle brush and remove any accumulated material. Follow by rubbing undiluted white vinegar on the car bumper to remove any remaining blotchy spots or mineral deposits.
Spread lacquer thinner, in a smooth layer, over the plastic car bumper, if the car has paint stains or paint scrapes on its bumper. Use a paint brush and spread lacquer thinner over the paint stains. Repeat this procedure several times. The paint will become lighter after each spreading, until it disappears. You can buy lacquer at a home centre or at a hardware store.
Place some car bumper or external vinyl cleaning gel on a rag or soft cloth. These gels blend waxes, solvents and oils to clean and restore plastic bumpers, as well as other vinyl and plastic car parts. Clean the bumper area with water and then apply the gel with a soft cloth or rag. Scrub the gel into the bumper with a toothbrush, if the grime appears ingrained. Reapply when necessary. Locate these gels in an auto supply store or through the Internet.