To make custom body kits, first determine the dimensions of the areas where the kit needs to connect to the vehicle. Make sure the length of side skirts is exact to sit flush with the vehicle wheel well.
Stick several foam blocks together using glue, and cut them into the specified design to form a piece for use as the mold for the customs body kit. Smother the foam with a sand paper. Use a body filter to cover the foam and leave it for two hours to dry. Spray the three polyester primer coats on the body filler top, and leave it to dry before smoothing the primer surface.
Wax the mold once a day for four days. Always allow it to haze before using a soft cloth to buff it. On one even coat, spray a tooling gel. Wait 15 minutes for it to turn tacky, and then brush one even coat of resin on it.
Break the fiberglass mat into pieces and set them on resin top. Roll the air bubbles out of the resin. Place five more fiberglass and resin layers on top of the existing ones. To pry the body kit out of the mold, use a wooden mixing stick and ensure the resin is completely dried.