I am not in the rust belt, but I figured, why not?
Now I know there are better treatments out there, but this one is the easiest to apply, does not need me to put the car on ramps (crawling under will do) while still having a proven positive effect.
This was my 2nd spray in 2 weeks of ownership.
What I did do:
-focus on the rear subframe assembly. This is the place where body on frame SUVs seem to rust first and the worst.
(As also evidenced on my 2008 Pathfinder which spent many years in the rustbelt).
-Sprayed into just about each frame hole in the rear subframe assembly a good squirt
-Sprayed into most frameholes in the rest of the frame
-sprayed onto some obvious body welds.
-sprayed the spare tire chain and the assembly holding that chain.
-sprayed all the bolts (that I could reach) that connect the rear subframe assembly to the frame.
What I did not do:
-Spray the whole outside of the frame.
This is a Nissan and Nissan frame steel holds up real well against rust.. (even my multi year rust belt 2008 Pathfinder has no rust issues with the frame itself).
Its the connections and rear subframe assembly you want to pay attention to.
Anyway, just thought I'd share.
PS: As long as I was at it, did some touch up spray, on my 2008 Pathfinder as well.