Check your rear wheel well lips where the two pieces of sheet metal come together. I was washing my car last week and noticed rust starting to form.



The bottom of the doors are like this too, along with the trunk and both rocker panels under the car.

 

I had to replace both my rocker panels on a 09 ss they were crumbling. Never put car in heated garage in a place with snow and salt

 

On an 09?! That's ridiculous.

 

Ya that's what snow salt and constant cold then warm will do.

 

I always wax the **** out of the wheel wells.

Also helps that my car never sees road salt

 

 

There are few good solutions for stopping rust. The cobalt doors are not finsihed to the same paint quality on the inside of the doors and that makes a difference. Its a metal return and can catch dirt and moisture. Same goes for wheel wells that are obviously a habitat for rust; in the same area near the exhaust over axle the fuel lines will rust through over time.

I beleive that annually oiling really helps, and fastidious car washing at least once or twice a week helps. Just rinsing out the wheel wells and brake calipers will be a big help. When washing the car, finishing up the inner door sills and door returns with a mitt and then a drying cloth will help a lot also

My redline only saw one winter, its an 04. My SAAB is an 07 and has seen every winter and has very little rust at all. The inner rear fender well in the spot welds has shown some distress, so rust paint and rust penetrating spray has helped stop that nonsense. Eventually these car will wear out anyway, if winter driven but regular oil spray sure helps. I pay 50 dollars for the under car application.

The key is the guys applying the spray. Its hard to find someone who is good at it, and pays attention to bumper to body seams when oiling, for example. Also if going inside doors and fenders, it pays to have some one who knows where the internal bulkheads are located and knows to remove the tailights for example and go in from either end to stop rear wheel fender rust.

 

I work in a body shop and Ohio really loves to lay the salt down on our roads so I see rust all the time. I can honestly say that somehow, as cheap as they are, cobalts in general don't seem to have much issue at all with rust compared to other vehicles of the same years. I'm not saying that you guys are wrong or anything, just saying it could be a lot worse than the rust on these cars. Powell is absolutely right though, oiling is key, especially inside the doors

 

I think you guys have the right idea with the annual oil sprays. I wouldn't do a rubber undercoating or anything like that, but on my next car (truck) I might give that a try. For now I'm going to try naval jelly or something on the wells and door in hopes of slowing it down. Rockers are a lost cause at this point as is the front and rear subframe.

 

Fluid Film guys, does wonders around here. Even the DOT is starting to use it on their snowplows, and I have a contract with school dept to use it on the underside of the buses to help extend the life.

 

How long does it last though? I don't want something that's going to wash away after a few undercarriage rinses.

 

A few applications a year is all you need, it bonds to metal and creates a barrier and stops oxidation. It's lanolin oil so it goes on thick, and holds up well to power washing.

 

Yeah I just read some reviews on it. Seems like great stuff. Definitely will try it this year before winter hits.

 

PS the solvents in some rust proofing products attack rubber. Rust check comes to mind.., choose carefully the products and find a good application guy.

 

Fluid Film is safe for all plastic and rubber, it does not contain any solvents.