Fluid Film provides amazing protection from road salt. After daily driving for 8 years in Minnesota, my ‘05 LJ is still entirely rust free.
View attachment 184034
It’s been my practice to spray into the frame though all of the holes in the outer frame rail and then plug those holes so that road spray and debris don’t get inside. I also pull down the rear wheel well liners and coat the inside of the tub down from the brake lights where there’s a seam (common rust area). Everything on the underside except for the brakes and exhaust also gets coated.
In past years, I would go though the car wash frequently, every day if necessary, when there was salty road spray. This past winter, I instead went under the Jeep after the first snowfall and sprayed any area I’d missed that showed salt residue. I went through the car wash maybe 10 times over the 5-6 months that we had snow and in between rinsed salt off the body with a mixture if water, soap and vinegar to neutralize the salt. I’ve found it’s best to skip the frequent car washes and instead let it do its job of creating a barrier between the metal and the environment.
Something else I‘d recommend regardless of location is
Frame Plugs. These go in the large holes in the outer frame rail and keep the sand, mud, water and other debris that gets thrown up by the tires from getting inside the frame.
