The plate background should be white but it caused me problems in processing so they are all in the standard reflective very light grey.
Usual format.
Transfer the .dds files (Plate_NM.dds and Plate_D.dds) into the chosen skin.
Remember to save the old plates if you do not want to overwrite them.
Making your cars individual is all part of the Kunos experience. Assetto Corsa cannot supply authentic plates because of the legal issues involved in selling the product for money. I however expect no return as I make these plates for my own cars and therefore like to share where possible. So the plates are quite legal to use.
Also check out my French, Italian, Moroccan,Belgian, British and Spanish plates.
I am looking at making Austrian, Brazilian and Eire plates for the future, possibly with some Dutch as well.
Enjoy.