Do you guys get your cars undercoated up north in the salt belt? If not it could help seal that out.

 

Mine was undercoated, yes but it's not like an oil spray or rust proofing with Ziebart or anything like that. Just the black undercoating.

I haven't even driven this car in snow or salt. I suspect a bad design in the rear inner liner and it holds too much moisture. It was mentioned earlier on in this thread. It's also possible that the first owner had body work done before and that is why it started slightly on the inner lip. I just found it "weird" that anyone who has had this problem had it start on the passenger side. I went and had a quote done the other day and the body guy said it was a shame that it started there because the paint is in very good condition otherwise.

 

So whats it going to take to resolve the issue?

 

Yea they will have to blend it and that would involve possibly going up the quarter panel some. Both sides, wow. That's too bad. Not like it's a cheap fix either.

 

To do a proper job where it won't come back after 2 years they will have to cut and replace the metal. I was quoted a ball park figure of about $1000 to do that.

I think having that whole section oil sprayed right after anyone has it done would be a good idea too.

 

When I stressed that it was important for the paint to match, most shops wanted to do each complete side...$$

 

Grease undercoat is the best as far as personal experience. Did that to my chevelle and my dad did it to his truck which is a 98 still zero rust. Cost about 350 to do whole car

 

Just had this on my 2007 Monte Carlo SS. Both wheel wells in the rear are starting to go. To echo what other people here have said, the only fix for this is to cut out the affected area, weld new metal in its place, and paint the area to match.

Took it to a local place today (that has a good reputation according to Angie's List), and to do the above they quoted me $1,000 even. Seems to match up with what others here are saying. A lot of work for the price!

Both the shop owner and the welding-master-guy stressed, however, that even with the fix it is only a matter of time before the rust returns. Couple of years, max. Informed members of this community: what is the actual, final solution to this problem? Replacing the entire rear frame of the car?

What does this involve, exactly? Also, how often need it be done? My '07 is my daily driver, even during winter, so it will be needing all the protection it can get.

 

Check with local places such as ziebart and see what they have to offer as far as undercoating. I would believe that grease undercoating would be an oil based mixture.

 

I talked with a lady at a car show this past Saturday. She has one of these cars and said she has the same rust problem with hers and just on the passenger side.