My guess is they bolted the bumper to something to dip it and this is why the plating is the way it is. If you've been in one of these plating operations (and most of the ones I've seen are hot any time of year and pretty nasty), you know they have a large tank of an acid mix into which they immerse items being plated and then have to haul them out again to rinse them a couple of times (different tanks). Small items may be on a wire which goes through a hole (in the part being plated), but larger items can't be done that way. When my grille bars were plated they ran two wires...one on each end through the holes.
That makes sense. Since it's electroplated, there has to be something connected to conduct the electricity.
I worked on designing repairs on the plating shop at the local Air Force Base years ago. They had a heat recovery wheel in the exhaust air stream that was supposed to transfer the heat to the incoming make-up air. When we went to look at it, the entire wheel was a heap of rust flakes laying on the bottom of the enclosure, and they were recirculating that acid laden air right back into the shop. Surprised that the guys who worked there had any skin left. LOL.
