I used almost a gallon of fluid film in my LC two years ago. It had no noticeable rust whatsoever, and was starting life outside without being garaged for the first time. This year, to my amazement, I noticed the cab corner (bottom in front of the drivers rear tire near the step) had rotted away. I had bought a wand sprayer at the time and sprayed that area heavily through one of the holes after removing the body plugs. I sprayed a lot in and it was leaking out for days. Not sure if the rust was already there on the inside or what, but to say I was disappointed would be an understatement. Again, I'm not knocking fluid film, in fact I'll try using it again. It should have helped the situation, I did a ton of research before using it. Not really sure what went wrong. It did end up being a very isolated area and I ended up getting new metal welded in. Once I get some paint on there, hopefully it'll be the last of my woes.