The front bumper cover has two fittings held to the inside with plastic rivets. Actually it looks like the fittings are placed on plastic posts that are then melted like a crushed rivet to hold the fittings in place. Most bumper covers from recycle yards are separated from these fittings which slide the bumper onto a similar part attached to the fender. The question is how to "re-rivet" the fitting onto the bumper. I could not find a thread on this subject although it must be one of the most common problems when refitting a bumper to the car.