I believe before season 10 all protection add-ons, like bumpers, roll cages, etc, were purely cosmetic.  They might have added weight, but no extra protection.  Since season 10, the add-ons offer actual protection, like +20% engine protection for bumpers, etc.  Please align the older trucks' add-ons to also add protection AND indicate the details (% and component protected) in the description of the addon.