If you have a problem with your car's CD player skipping or repeating, even when you're not moving, then you probably need to clean it. There are a number of simple products on the market to help you clear the player of any dirt, dust, or other issues that could be affecting the play quality. Your car's CD player is very similar to a standard player when it comes to the cleaning process.
Purchase a can of compressed air. You can find one in a computer store--they are commonly used for computer keyboards. You also need a mild household cleanser (or you can make one with 3 tablespoons of vinegar to 2 cups of water) and a CD lens cleaner kit that is specifically designed for a car's player.
Remove all CDs from the player and shut off your car.
Open the tray (if there is one). Spray the mild cleanser onto a rag and wipe the tray down thoroughly. Use a dry rag or paper towel to remove all moisture.
Stick the nozzle of the compressed air can into the side of the opening of the CD player. Spray it thoroughly to blow out all dust and particles that may be inside.
Prepare the CD lens cleaner per the instructions. The lens cleaner contains small brushes that clear the lens in your car's CD player. Insert the CD lens cleaner and allow it to "play" until it stops or the voice on the CD tells you that it is finished.
Remove the CD and insert one from your regular collection to test the player.
Wipe off each CD on a soft surface, like a T-shirt or the upholstery on your car seats, before you insert it into your car's player, to reduce the chance that dirt and particles will corrupt the lens.