The differential cover originally had little-to-no paint on it when the Firebird left the Norwood plant, and it rusted immediately. Rubberized undercoating applied at the dealer gives it much more visual appeal. This aluminum tag noting the requirement of limited-slip differential lubricant on this particular example is in the 5 o’clock position and it’s formed to the shape of the differential cover. The tag is often located in the same position on other cars, but points in virtually any direction. It was seemingly up to the installer.