I also have a 2006 Monte Carlo SS which I purchased new. I have babied this car since day 1. I only have a little over 33,000 miles, I have it washed and detailed on a regular basis and was sick to find after this last detail of a week ago, rust on the passenger side rear wheel well extending out to the fender about the size of an eraser head of a pencil. I've been told to get rid of it because it will just continue to rust as it is rusting from the inside out. I can't get rid of it. I love this car. Other than this rust issue, it looks like a new car. And plus, since they don't make this model anymore just what would I replace it with? Plus I can't afford a replacement. I am just sick about this whole issue. Any suggestions besides a body shop replacing the whole fender and side frame of the car, etc., etc.? Will GM do anything about this? I see it is not covered under my extended and again extended warranty.

 

Mine is rusting, in front of rear wheels.

I have the GM RustGard 10 Year warrantee, I paid the dealer for rustproofing.

RustGard refused my Claim, Dealer won't do anything about it. The owner offered me 1/2 price on the repair, their estimate was 1,458.00. 1/2 was over 700, plus tax, which I didn't have last year.
Now the driver side is rusting through as well. And now the dealership has a new owner.

Let me know if/when you find new fenders.

 

To the OP - you are talking the rear wheel area. That is not a fender, it's a rear quarter panel.
Fenders are bolt on, but rear quarters require cutting, welding and filling.

A member here did his own rear quarter swap on a 5th gen monte. Lot of work and looks like it came out very well (especially for not having done it before). Even though the cars are years/gens apart, his post may help understand what's involved to repair that spot.

 

Well hello and Welcome to the forum!!

If it makes you feel a little better what your experiencing most of the 06-07 Monte Carlo owners have or may experience. The wheel well rust is apparently happening from the wheel well liner trapping moisture. The 2000-2005 did not have this issue. But leave it to GM to re-invent the wheel and well you have this particular issue. Think the proper fix is to bite the bullet and get the fender sections cut away and new metal installed, then SEAL the liner to fender abutment with a rubber butyl or such to prevent any moisture from ever again being trapped there.

Now the cheap fix is probably a "rust arrestor" type product from behind and to the now sanded / prepped bare metal on the outside, then bondo, primer and paint it yourself. But again, this is only a band-aid. Probably depends on how dilligently you do this repair method before the rust once again pops it's ugly head through your painted surface.

So your not alone with this issue, this problem is prevalent many owners do feel GM should have a recall for this, but alas GM has washed it's hand of any fixes. Stupid liner anyway...

 

Welcome to the forum...

I had the "Typical" 5th gen rust that Greg (zippy) mentioned earlier...
I took mine to a shop over the winter and it replaced with new metal and repainted... Theres no guaranteed rust repair fix that prevents it from ever returning unfortunately... However, there is a product called PORS15.. Its suppose to stop rust dead in its tracks...for good! I haven't used it as of yet... However... I am over the winter going to use it on the inderneath where my repairs were recently done... As an added measure of protection!

I also have some surface rust starting on my rear strut mount towers that I am going to apply it to.. Now my monte is 14 almost 15 yrs old with well over 169,000 miles on it... It was my daily driver from the day I ordered it from the factory ..it too was rust proofed at the factory.. as well as sound proofed... Just until this past winter its no longer a daily driver.. Like you I too babied mine.. and it received regular washs and waxing... Its inevitable..It will begin to rust.. Considering your Monte is already 8 yrs old I would say your actually lucky that's all there is..I don't know what state you hale from..But I reside in Michigan... and Rust is inevitable where I live.. Especially since Michigan uses salt on the roads during the winter months...Which is rusts best friend (IMO)... If you love your Monte as much as you say you do... Save up the cash and have it repaired... you wont be sorry.

 

Yea. Signed up just to post. My 06 LT is rusting out passenger rear wheel well. Dealer where I bought it new says the 100k mile body warentee won't cover road chips. Obviously it came through from the inside. 20g down the tube. Done with gm forever and I have owned nothing but gm through the years. Took it to multible Chevy dealers. Same story. Talked to a local body guy I trust. He said. Yep. Known problem that gm denies. There is a design flaw.