cases, there are hidden bolt underneath the license plate ,so you need to remove the bumper first. Sierra Cosworth has license plate on top of the rear bumper, so most likely it has hidden bolt underneath the wheel. You can carefully pry open center lug(cover) and there's bolt there ,so you remove the wheel.
Then you can see if there is a bolt there or not. Sorry couldn't help you more. I did take one apart a long time ago and can't recall where all the bolts were. However, there is no glue holding the chassis. This is Sierra Cosworth Touring car correct?