This ad is for a genuine Ford Mustang Trunk Lid License Plate Housing Panel. It is not primed. 

I think it will fit from 1994 to 1998, but I am not sure 100% about it. Please check with the dealer if you have other model than the years stated on the title to make sure it will fit before you buy. 

This has never been used, but it has been sitting in bulk storage and may have some small cosmetic flaws. Since it needs to be painted these flaws should not matter at all.