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Rust proof now?

Hello Yall,

Recently took on my first car payment. Had to start “adulting”. A bit of quick back round : I am 28, living on the Texas coast( hot, humid, windy, beach). My first car was a '03 Ford Escape. I had it til this past December. Just shy of 200k miles. So, needless to say, I keep my cars for a long time. And I keep them up.

The car I purchased- Used: '14 VW Tiguan with >34k miles. I had it tinted recently. South Texas sun is brutal. We are an outdoorsy family. And my car was previously a rental. So it has basic features. Since I do plan on having this car for as long as possible, I am wanting to do some upgrades: floor mats, luggage rack, trailer hitch, scotch guard the seats, etc…

This bring me to my question(s): Should I get it coated underneath sooner rather than later? Any other suggestions on upkeep for living down here? I feel it something I should invest in soon, because we do live with in a mile of the water. My husband and I go back and forth because I am afraid of how much it’ll be, but I truly believe it’s a worth while investment.

Thoughts please?!


You’re in Texas. Unless you’re right on the Gulf, you’re fine. Your car will be rust free long after mine is swiss cheese. And if you are right on the Gulf, no amount of undercoating will save the car. The salted humidity will attack it everywhere. Undercoating won’t prevent rust from forming in that tiny hairline paint crack you never noticed on the roof.

Do not undercoat the vehicle.

Undercoating can promote rust rather than prevent it if not applied correctly.


I wouldn’t. Probably/almost certainly wouldn’t help, and I can’t think of who in TX would know how to do it.

My opinion: added rustproofing is never needed, and may cause problems, as it can trap salt against the metal. I live on the east coast, and haven’t had major problems with rust since the 1950’s, although I don’t keep cars past 12 years or so.

Cars today have (supposedly) adequate rustproofing from the factory.

For floormats, I like the weathertech line.

Neither would I.

Modern Cars Don’t Need Additional Rust Proofing/Under Coating. You Can Actually Create A Situation That Accelerates Corrosion By Doing So.

Yep, undercoating is not rust proofing and undercoating can actually promote rust. Rust proofing is really not needed anymore either since most manufacturers have provided this already at the factory.

Most (All?) New Cars Come With A Specific Body Corrosion/Rust-Through Warranty.

I’d read the warranty (with your Owner’s Information) and/or contact the manufacturer. I have seen situations where applying rustproofing/undercoating to a vehicle will actually VOID the manufacturer’s warranty.

Even here in New Hampshire I don’t get rust proofing. Keep vehicles for 10+ years and usually over 300k miles…no problems with rust what-so-ever.

Rust proofing has gotten a bad rap over the years. It DOES WORK…but it has to be applied properly. Back in the 70’s and early 80’s I’ve seen identical cars where one was rust proofed (Ziebart)…and the other wasn’t. The vehicle that wasn’t was rusting away after 5 years…the Ziebarted vehicle wasn’t showing any signs of rust even after 10 years.

The problem is it has to be applied correctly by someone properly trained and takes their time to do a proper job.

Modern car manufacturing negates the need for rustproofing. Materials are very different now, conformal coatings are used just about everywhere, seam welds (welds create rust prone “Heat Affected Zones”) have been replaced with spot welds and even in many cases bonded joinery. Engineers have also learned how to control the flow of water as well as to allow drainage from and ventilation of any unavoidable cavities.

That last point is important to note, because the application of rustproofing can interfere with the ability of body cavities to drain and vent and can actually promote rust.

I recommend you do nothing. New cars are designed to prevent rusting. When I was your age that wasn’t true.

By the way, I commend your doing the research to do the right things. Properly maintained, your new car will give you many years of reliable enjoyment.

Agree with others; rustproofing is already done at the factory. And adding it after so many miles can actually do more harm than good. Just leave it alone. Personally I would not invest any money upgrading in this vehicle since Volkswagens are typically not long lived in terms of economical performance. If you spend enough money you can keep them running, of course.

A nephew of mine runs a Pawn Shop and he has bought a number of VWs with low mileage for his wife. At the first major repair he “sends it to the crusher.”

By year 10 you will likely have very major expenses that may end the vehicle’s economic life. Keep in mind that Germans drive less and get rid of their vehicles after 4-5 years; these vehicles are then exported to Eastern Europe and Africa, where labor is cheap and regulations very lax.

If all this seem gloomy and pessimistic, I have a number of friends who have gone through tis; VWs are not long term vehicles these days.

eing a rental car you might just be sealing in salt, as yo do not know where it has been, Brand new or never rustproof my thought.

I would worry more about repairs and maintenance, then rust on a VW.

Good advice above. Focus on keeping the routine maintenance up to date. Good quality heavy rubber floor mats that keep any water from your shoes trapped on the mat and not running off the map and onto the vehicle’s floor/carpet are definitely worth the expense. I bought some for my Corolla like that 20+ years ago, and they’re still good as new. But it was so long ago I can’t even remember where I bought them, let alone the brand. Rather than scotch guard I’d recommend some seat covers. They don’t need to be super-expensive kind, the less expensive kind work fine as long as they fit well. Just replace them as soon as they wear out is all. Since you live near the ocean it would be a good idea to wash under the wheel well areas, spraying down there with a garden hose once a week or so. It will minimize the amount of salt accumulation in the wheel areas.

I wonder how rusty the body on the former vehicle became to inspire this interest is “under coating”.