I dont think they realize that the Monte aero decklid is absolutely useless. it's taller than the GN lid because of the GN taillights. The monte has a shorter width wise decklid. you pretty much have to modify a notch back GN/cutlass decklid to fit the application. and that may be the same for the shelf, you may have to fit extentions to fit it in a different car. i put my monte aero decklid "on" a GP trunk opening and it doesnt reat on anything because the GP has a wider trunk opening. Hope that makes sense to someone. I can photoshop a diagram to show you what I mean if neccesary. Not trying to discourage anybody from trying it, just saying its not a drop in application