An ascMcLaren forum for 84-86 Capri and 87-90 Mustang based cars modified by Automotive Speciality Corporation, a Division of American Sunroof Corporation. (no affiliation)
They will be bolted to the body just behind the doors. I doubt asc would have encased them. You will probably need to completely remove that entire rear area to get at them.
1985 ascMcLaren Coupe - Midnight Blue
Under Restoration