Originally Posted by
Jorge T
The hole is less than 2.5mm in diameter. A 3mm bt head or set screw should thread tight enough.
So I went and looked at mine last night after this and an M3 screw goes right through the holes. Maybe the one in the bumper is smaller (hard to tell if my screw went through both pieces since my transponder is mounted above the center hole) but the hole in the chassis is definitely 3mm.