An article that detailed the build of a 1:24 resin 25th Anniversary 1990 Mustang LX 5.0 Convertible appeared in the June 1992 issue of Scale Auto Enthusiast. This car very clearly resembles a 7-up car and this information could serve as the basis for a Feature Car build.
Mike G. built this replica of his 1992 Feature Mustang. There is no single kit for this car. Mike described the build:
Fellow feature Mustang owner Bill sent me this picture of a model he built of his car. Unfortunately, there is no single kit for this car. It is built from pieces from several Monogram Mustang kits as well as a front clip from a resin 87-93 LX Coupe since all plastic kits of 87-93 Mustangs are GTs.
I have Majorette #227 which, although it is not intended to be a feature Mustang, is a yellow Mustang convertible with a black interior. As far as I can tell from research, this model number car was offered from 1988 to 1994 in several different colors and with slight variations.
In late 2005/early 2006 GMP released their replica of the yellow 1993 feature car. There was some discussion of it on this site in the forums. As of this writing I don't own one myself. It is my understanding that they are making these in limited quanitities of which I have seen a couple numbers (1750 or 3000).