In 2020 Audatex DBRM was updated with new FAQ (Frequently asked questions) regarding refinishing of the back side of replacement panels.
Question: Does Audatex refinish times allow for refinishing the backside of the panels like fenders and quarter panels?
Answer: The replacement refinish allowance for fenders and quarter panels does not account for refinishing the backside of these panels. They are not typically refinished in the repair process.
Repairers may have instances where the actual backside may not need “REFINISH” but rather additional “Corrosion Protection” product application of labor and materials to replicate the factory appearance and corrosion protection properties. It is always important to reference the OEM’s Repair procedures and following proper corrosion protection steps.
Example below is from Honda 2020 Corrosion protection document
Article from: https://degweb.org/estimate-toolbox-parent/estimate-tips