You said -
quote:I use sheet metal screws. I like to spread out the contact patch by cutting 2" lengths of a 1/4" hard plastic tube, drilling them in the center (like a Propeller) and running the screws through the drilled hole.
Just to make sure I understand, you install these 2" plastic tube 'propellers' between the air dam and the car body everywhere you have a sheet metal screw?