I apply Fluidfilm from an undercoating type gun to the entire underside of my daily drivers every fall. I use wands and hose attachments to get in every crevice I can. A nasty smelly greasy job to be sure but it keeps the car payments away! WaxWool is the other brand but I can buy Fluidfilm by the gallon at the local John Deere Dealer.
Application gun and attachments.
This is my first year using Fluidfilm and Waxwool, let's hope it works, it is messy ! I finally had to unload my '89 Toyota pickup because I couldn't keep up with the rust damage
'65 A-code coupe, T-10 4-speed, 8" 3.25 limited slip