The only differences I ever noticed is the angle & height of the base. Then depending on the year, the mounting studs maybe inch or metric. The OP should just run with then. Might notice the angle difference but only if he really looks at it.When I replaced the driver side mirror on my LeMans I used one off a 4 door Cutlass, it changed out just fine and looked identical, if there was a difference I didn't notice it or maybe overlooked it. I assumed the sport mirrors on all 4 doors/wagons are the same, from a glance they appear to be.