I've never seen the bumpers attached using the same screw as the cover before something I'll watch for.
My Orange car has the bumpers out near the ends and the same on both sides. The Black car (4000 mile car) has one in the middle (like in the pic) and the other side out near the end, totally different from one side to the other.
The Green car also a original owner car has no bumper, it's a last week of Feb. Norwood car. I believe the bumpers started sometime in March but have'nt got it narrowed down yet. I think the bumpers were added to support the ends of the spoiler so they wouldn't crack or break if someone leaned on them.
I've seem where some hit the quarter panel and some 3/4" above, so I don't think they had it down as to were to put them.
