Do you need underbody rust protection on new Prime?

Once upon a time when I was an apprentice mechanic, one of my big jobs was "rustproofing and undercoating".

It's only actual function was to remove several hundred dollars from the customer's pocket and add them to the dealer's bottom line.

If anything, "rustproofing" may well hasten the rusting and deterioration of some parts of the vehicle as it tends to clog up drain holes that let water OUT of doors and the like. The access holes drilled by companies like "Ziebart" also were great places for rust to start.

Anyplace that sells the "service" is likely not gonna do a job that will help much.

OTOH - if you're a committed owner and are willing to spend the time and effort to do it yourself - you probably can accomplish a decent job that will slow down the rusting of your vehicle.

Best done when the car is brand new. Getting all the dirt, water, chemicals, existing rust out a vehicle is probably about impossible.
Yes - all the plastic panels will have to come off.

Several different rust preventative products have already been mentioned here - so I won't add to that confusion.

As for "cars being built to resist rust better now" - I would disagree.

My cars built in the 60's and 70's stayed alive longer than the ones from the 90's and 00's before rust destroyed them.
I had brake lines on two later vehicles rust through and fail in less than ten years. WELL less than 100,000 miles.

GM started using half-galvanized panels for doors back in the 80's.

So even if the body looked better after five years - the parts UNDER the car were worse.

 

I’m with you there. The suspensions and associated bolts on our previous Honda’s seemed more rust resistant. A combo of galvanizing and recently-banned coatings maybe? Bodywork maybe not as good though, there’s that.

To topic-drift a bit, seems like with almost everything these days, flimsier, more plastic, and corner-cutting are in the company “mission statements”

 

I know of my OLD '64 Dodge Dart - the brake lines were actually lead-coated - never showed a speck of rust after 20+ years.
Lead being the element it is, probably "banned" for that purpose.

The brake lines on my '96 and '06 Ford Mustangs were just plated with something that didn't last long when exposed to Chicago winters. They both perforated in less than ten years. Same with my mother's '96 Grand Prix.

Ironically, a brake line on the '06 Mustang that crossed the front of the vehicle had a plastic coating along part of it's length. Under that coating - it was clean, unblemished metal. Right next to it, rusted through. (Um, why didn't you coat the WHOLE line Ford!?)

If I had a lawyer - I would have taken that one to court. Luckily I avoided an accident - but the piece of evidence in my hand would have convinced a jury.

 

The elephant in the room is road salt. Gov’s should look into less rust-promoting alternatives; there are some contenders.

 

Sure, road salt is the biggest culprit.

Chicago uses hundreds of tons of the stuff every winter.

I know there is a molasses-derived substance that I even see used around here (NE Texas) on bridge decks and the like. I'm sure it's many times more expensive, but since governments don't pay for replacing rusted-out cars, that's not a factor for them.

I'm sure the deleterious effects of road salt also goes far beyond rusty cars and some dead right-of-way vegetation.....

 

I would not worry about rust in suspension components. Some of those get replaced way before corrosion damages get too far. It’s the underbody which need attention because welding of modern cars is PITA. So much wires, clips, etc etc..

Even if (and when) underbody is covered with plastic panels i would spray some inhibitor every now and then regardless of car brand. I had 2006 Volvo V70 and after 10 years and 300kkm the underbody looked absolutely beautiful. I don’t know what silverish stuff they had applied at factory but it looked spotless and amazingly clean after so much driving. We were working on tailpipe hanger which had given up due to rust (yes), and mechanic said he had never seen old car underbody looking that good. But, i hear later V70 generation is worse.. Saving pennies and weight. It’s sad. It even compromise safety at older age of the car.

edit: managed to find picture. Is that beautiful or what

 

Volvo uses Noxudol.

Rust Proofing by Noxudol | Car Rust Protection | Rust Proofing Spray