The factory engineering department was very conscious of the need for these support rods, and that is why they were installed. When the cars came in for service, many times the support rods would need to be removed to do the service, and not replaced. The people doing the work felt that to replace the part that in their opinion wasn't needed, is a waste of time. I recently gave instructions to someone on how to remove a dash pad. At the end, I also commented that the one retaining nut in the center of the dash pad was difficult to remove and reinstall, and if the dash pad had been removed in the past, most likely that nut wasn't replaced. My feelings are that if the factory installed the part, the engineers felt that there was a need for the part, and that it should always be replaced. Others don't always think this is true. The only time that the factory might deviate from one model to the other, is when one part would interfere with the placement of another part.