A friend of me lost his faceplate while he was drunk on an open air festival. He tried to get replacement from panasonic- no way even on the cheap model he had.

So he had to buy a new one.
Today if you buy car stereo you'll have to keep the bill / receipt or a kind of ID card ( i ve one for my blaupunkt) to get exchange faceplate or Keycard etc.. .
Its unfair but its security to prevent bad people of stealing your stereo.
Felix