So some idiot (not me) decided that the best way to access some bolts behind the active aero tray was not to remove the tray, but to cut holes through the tray. So I’m patching those holes with the same ABS plastic sheet I used to make replacement access panels.
Here’s the holes and the patches. I cut a smaller circle to fit the hole, and a larger circle to patch from the back side. I’m using 3M Industrial Plastic Adhesive (part 4475). It claims to dry flexible and clear. I scuffed the side of the plastic to be glued with sand paper to improve adhesion of the glue.
Test fitting the patches:
A view from the back side (note: one side of the ABS plastic sheet is textured, the other side is smooth):
Not exactly pretty, but it will do the job aerodynamically, and it’s not really a visible area of the tray.