I was looking for a way to prevent my new 2017 Mustang from rusting. I live in Canada and here we use salt in winter. I asked a lot of people how I can protect it, and each one says something different. The dealership wants to sell me an overpriced rust proofing kit and I don't think it is my best option.

My options are:

  • Keeping the vehicle covered outside, maybe do an oil rustproofing.

  • Renting a covered heated garage. If so, I already used my car over salt so should I wash it before doing so?

  • Installing winter tires and use it as normal; maybe cold weather and ice will prevent rust from forming.

  • 1
    obviously storing it and not using it all winter is the best thing you can do. No need for the garage to be heated. Whether that makes economic sense vs enjoying it and trading it in before it rusts is another matter.
    – agentp
    Nov 28, 2017 at 21:43
  • And should I wash it before doing so? Because I already used it one or two days over salt
    – achref
    Nov 28, 2017 at 21:49

4 Answers 4


The deicing salt put on the road gets splashed all under the chassis greatly promoting rust. Best prevention - Never drive on a road that has been salted , once exposed to salt it is about impossible to remove. Covering will not help. Rinsing the underside does little good ; A friend of mine did this religiously and it made no difference. Heat is little help because it lowers humidity, But many salts are hygroscopic so you can't get it dry enough. The asphalt type rust proofing are no help . An oil with a corrosion inhibitor sprayed on the chassis does help ( we did it in a lab so I don't know if there is a commercial product). Mostly you depend on the manufacturer to eliminate locations that hold water/mud, and to apply zinc during manufacture.

  • So if I just wash the car thoroughly from the salt that already got in (used it only one day over salt) then directly store it in a covered garage I'll be completely safe?
    – achref
    Nov 28, 2017 at 21:49
  • Keep the car clean to keep all the road salt off it. There are sprays etc.. that you can spray to help prevent it but rust will always be there where moisture is. You can use an oil called fs365 (its a mineral oil), Spray it on a clean vehicle and then respray after every wet drive, this will stop all the dirt and sat drying and attacking the metals.
    – DamoC
    Nov 29, 2017 at 0:15

Por 15 ? Gets stronger with moisture .


You are very fortunate to live in Canada as you have available to you very effective rust preventive treatments. These are chemical sprays that are applied annually by dedicated shops. The chemicals were developed initially to protect North Sea oil rigs. The shops who apply it guarantee that your car will not rust if treated every year. It is really quite something to watch them apply the product. They drill small access holes, run tubular metal wands through them and pressure spray the inside of panels with the chemical, then plug the hole. It sounds scarier than it is; you don't notice the plastic plugs. The chemical has remarkable creep; it travels beyond where it is sprayed to protect all the nooks and crannies. Cost is roughly $125 per application. Franchises who apply these treatments go under the trade names Rust Check and Duratech (Quebec), and probably others. Rust Check was the first, as far as I know. There are a few Rust Check shops in the northern US states: I have found them in Syracuse and Duluth.

I have a 2003 Honda Element that I had sprayed the first weekend that I owned it (new) and then again three years later, and again three years after that. That is all. No rust after 15 years and 307,000 miles in Iowa, Seattle and mostly Connecticut. My mechanic always comments on the rust free condition. Plenty of battle scars but no rust!


Salt proofing usually means spraying whole underside in black waxy gunk, simply not worth trashing whole underbody like that, and it will also cover all the suspension components, cables, fuel and brake lines. Any later work will be very dissatisfying.

Salty winter mud is terrible for cars, even brand new zinc plated parts turn into dull gray old parts after only a few months!
I'd rather spend money on full underbody washing, at least after the salty season. The best would be washing the car every day, especially wheel arches, brakes, sills.

Also to protect the radiator block lower ports in the bumper with some plastic foil and zipties, as there where the radiator gets stuffed the most, and basically it can't be later washed out.

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