I have not needed undercoating in my last 3 or 4 vehicles, and I kept them for many years.
Clear water spraying underneath, a day or two after the salt was applied, is all I did to them.
Plus, I never kept them in a heated garage.

 

X2 on this. Just take the time to spray everything off real well. Has always worked for me as well.

 

Even though we don't live in an area that see's salted roads,washing with water especially in places like inside of frame rails helps a lot

 

I find this interesting, as a NorCal resident.

Live where your vehicles last forever, or where houses are affordable?

 

Do they use a lot of salt there? I would think that sand would be the choice there similar to Reno/Tahoe. Anyway, I've use Fluid Film with good results.

 

The only thing I do is rattle-can the frame every year or two. It's doing quite fine after 5 or 6 years later here. I like the Rustoleom "rust converter" stuff. Like $5 a can.

The frame is really the only thing that picks up rust on my JK. There was a little out back under the rear of the tub too, but I caught it quick. Oh, and the side-step brackets got very crusty. I figure they take a beating.

 

On our roads, the winter salting is not the biggest problem for me. They do not salt anything besides state highways and in town anymore, and I spend most of the time on back roads. The bigger problem is that they use salt water for dust control on our gravel roads. When it rains, that salt/clay mix turns into a nice brown coating on the Jeep from the frame to the windows.

Makes no sense to wash it in town, since it would be covered again by the time I get home. The solution is to drag out the power washer whenever we have a few days of dry roads. I got tired of that years ago. She gets washed and waxed 3 times a year (and looks good for maybe 2 or 3 days) and then goes back to being a hard driven half brown and half red country runner.

I just replace the vehicle every 10 years or so when the body/frame are too rusty. I wear them out by then anyway.

One less thing to worry about.

 

FWIW, I've had vehicles with that rubbery tar-like undercarriage coating, and I did not like it. Rust still got in or around it, and it flaked off in chunks. Made working under there not very fun. I very much prefer just attacking rust with spray paint.

 

On my past vehicals and this current jk.. I am constantly emptying rust check cans underneath and in doors and seems..always worked for me

This new jk I am second owner..the first owner installed that gimmick rust stopper that connects to your battery.i have no idea if it works.I am in ontario Canada. .so I see lots of salt

 

I use 3M rust fighter on the underbody seams thats where the rust generally starts. It sprays on like an oily foam that solitifies a bit into a thin parafin stickey wax water just beads up and runs right off of.