There is a length of rubber seal that needs to be affixed around the perimeter and a large round grommet that goes in the hole before the heat shield can be installed on the car. The seal just snaps on; make sure to start at the bottom, which will leave the seam out of sight. The large grommet will slip in the hole by hand. This bracket will mount to one of the factory studs with the stock nut. The heat shield slips under the core support on one side so this single nut will be the only mounting point necessary.