A side skirt is the part of the vehicle screwed to the bottom side of the car to complete the design of the car and to protect the bottom from dirt and other materials that can damage the surface of the car frame. Many people replace the side skirt that originally came with the car with an after-market skirt that changes the look of the vehicle. Installing these side skirts is an easy modification, and sometimes changes the car's appearance drastically.
Remove the screws holding the original side skirt to the car, using a Phillips-head screwdriver or a ratchet. Set the original side skirt aside.
Place a few drops of dish soap into a bucket of warm water. Clean the area of the car where the new skirt will be fastened, using a soft brush. Dry the area, using a towel.
Place the new side skirt against the car for fitting. Note the location of the screw holes on the side of the car. Mark the placement of these holes on the new side skirt with a grease pencil. If the skirt is too long, cut it to the correct size with a saw.
Drill holes large enough for the screws to fit through on the marked pieces of the side skirt.
Line up the skirt against the side of the car once more. Draw an outline of the skirt where it meets the car, using a grease pencil. Set the skirt aside.
Place a line of double-sided tape 5 cm (2 inches) below the grease pencil line. Do not block any drill holes if possible.
Peel off the tape backing and press the skirt firmly into the surface of the tape.
Screw the new skirt in place, using the screws and bolts that came with the new skirt.
Drill a hole into each of the wheel wells on that side of the car where the skirt hits them. Secure the skirt to the wheel wells, using two small screws and a Phillips-head screwdriver.
If the skirt must be painted, take the skirt to an auto body shop to match the skirt colour to the colour of your vehicle. You can also paint the skirt a coordinating colour instead.