It is a legal requirement in most states for drivers to have front and rear number plates attached to their car. It is therefore very important to avoid a fine by making sure number plates are well attached and don't fall off. There are different methods of attaching number plates, none of which should take more than half an hour to complete.
Check the plates to see if they require two or four screws. Some cars come with screws already fitted into pre-drilled holes on the bumper or rear panel.
Remove the screws from the pre-drilled holes in the centre of the bumper or boot panel. If the car does not have any pre-drilled screw holes, place the number plate over the bumper or panel and mark holes with a pencil. Drill these pencil marks out using a hand-held drill to match the screw size.
Use a screwdriver and fitting screws to fix the number plate into the holes in the bumper or rear panel. Start by tightening the screws by hand before using a screwdriver. Make sure the number plate is securely fitted in place. The number plate may bend to follow the curve of the bumper.
For expediency, instead of using screws, try fixing the number plate using several strong double-sided adhesive patches available from hardware stores. Peel off the backing and fix them to the back of the number plate. Carefully stick the number plate to the fender making sure the plate is not crooked. This should help if you are temporarily unable to attach the number plate using screws.