How to Install Mud Flapsby Contributor
Check your wheel wells for push-pins where mudflaps would attach. Some cars have push-pin retainers that you remove and use to attach the mudflaps. If your car doesn't, use a drill to install your mudflaps.
Park your vehicle on a level surface. This will help you install the mud flaps straight. Loosen the lug nuts on the wheels in the wheel wells in which you want to install mudflaps. Lift the vehicle at the appropriate jacking points and support it on jack stands. Remove the lugs and the wheels to give you more room to work.
Take your first mud flap and position it inside the wheel well of the wheel on which you want to install it. Make sure that the decorative side is facing toward the rear and that the mud flap is the desired distance off the ground.
Chuck a drill bit in your drill motor that matches the size of the screw shank for the mounting screws. Drill a pilot hole in the top of the mud flap and through the wheel well at one side. Insert a screw and secure it, but don't tighten it all the way. This will allow you to adjust the mud flap to make sure it is level.
Use the level to adjust your mud flap and make sure it is lined up and level. Drill a second hole on the opposite end as the first hole and insert another screw. Check again to make sure the mud flap is level.
Tighten the screws. Drill more holes and install the remaining screws for that mud flap. Make sure that the screws are all tightened before moving on. Repeat the steps for the other mud flaps for your vehicle.
Put the wheels back on and tighten the lug nuts hand tight. Lower the vehicle to the ground and then torque the lug nuts in a star pattern. Check the torque specification for the lug nuts on your vehicle.