What if he means that some cars have got their black painting around the grille removed, and instead have a polished (chrome-like) surface? As far as I know, this is a "home-made option".
A thing that I have thought about is that there seems to be two different grilles on ยด70 Challengers. One that is argent and the other is....? (One that fits the R/T:s and another for the rest)
(The difference is not very obvious, is it?)