Abstract: A wheel cover retention system includes a series of plastic caps carried by the wheel cover. The caps have integral flanges engageable with flanges of the cover to hold the cover against the vehicle wheel when the caps are threaded on exteriorly threaded lug nuts of the wheel. The caps have integral legs which extend therefore through the cover with these legs having barbed ends to prevent separation of the caps from the cover. Interlocking ribs on the cap flanges and cover flanges resist relative rotation between such flanges when they are engaged to resist unthreading of the plastic caps from the lug nuts when the wheel cover is mounted to the wheel.