When you mean aftermarket, are you talking about a non cracked one or the covers into black area of the grill?
I am going to Ace Hardware and buy either 2 or 4 sheets of the diamond cut, thin sheet metal, cut them to size, and insert them with the existing screws into the black areas.
rbrettctd did something similar.
Jon 93 D250~ Mismatch of cheap parts, trying to look fast going slow