When vehicles are sold across multiple markets, one issue that arises is the different sizes of license plates. For example, Japanese and North American license plates are fairly similar in size, disregarding mounting hole placement. Australian license plates are a fair bit different in size and shape. European license plates are quite different in this regard.
Often time manufacturers will size the license plate well to comfortably accommodate the width of a European license plate and the height of a North American license plate. In this case, different mounting hole locations need stamped, but the basic panel can remain the same. Other times, the license plate is mounted to the rear bumper cover which is often cheaper and easier to re-tool compared to a stamped steel body panel.
In the case of the first generation CR-V, a mix of the two was chosen, with an interesting twist.
Both the North American version and the Japanese version of this CR-V have a rear door mounted license plate. Each market likely used a different plastic insert for the well, but either insert fit into the well on the door.
However, there was an issue with the European and Australian markets. Due to the length of their license plates, the well designed for the Japanese and North American markets was not long enough to accommodate the license plates. The length of the well could be increased, however, it would then interfere with the placement of the spare tire - space was at a premium. The solution? Mount the European and Australian market license plates on the rear bumper instead of the rear door. It appears that the rear bumper needed to be redesigned for market specific lighting requirements anyway, so moving the license plate to the bumper was no big deal.
However, something needed to be done about the license plate well that was already in place for the Japanese and North American markets. Honda likely did not want to create an entire new rear door stamping for these markets. Thus, a decorative fill panel was implemented.
Honda would stick with this solution for the second generation CR-V. The license plates for all markets would appear front and center on the tailgate for the third generation with the deletion of the door mounted spare tire.