Since our car is a mesh of previous gen MB cars (SLK, etc.), I went to MBWorld and did a search. Looks like we may not be alone with this issue, though most of the threads are older:

http://www.mbworld.org/forums/showth...st#post2309472

http://www.mbworld.org/forums/showth...ust#post760781

http://www.mbworld.org/forums/showth...ust#post388514

This is a bad, bad thing. Think of all the unsuspecting Crossfire owners out there with rust eating up their doors. Grrrr.

 

The wing is plastic/fiberglass. Is the panel it attaches to (the part that looks like a non-SRT wing) plastic as well?

 

The wing attaches with 4 bolts through the truck. The wing fits snugly into a slotted area and is tightened flush to the deck or trunk lid. The rust is actually on the trunk lid of the roadster.

 

Thanks Randy.

 

Wow. As a new owner, I can't believe the rust that appears on these new cars. Its a bit scary. My Porsche was 21 years old and not a hint of rust anywhere. I know it lived in Ill. Ohio, and Fla., so many chances of rain/snow etc. I bought this Crossfire for the looks. I'm just wondering if DM screwed all of us with a "soon to be lemon" in this area. I'm already concerned about the no spare tire issue. I'm going to look under everything tomorrow and check it out, because I will not put up with any rust, period. There are way too many cars on the market which won't have bad rust problems. They might cost more, but hey, it could be worth it in the long run. I have visions of keeping this car for a very long time, and it should last a very long time the way I keep and tend to my cars. But if I suspect anything else, I'm out of here faster then a bullet.

 

Strupgolf, I feel your pain, I really do. But I honestly think this is one isolated design defect that has been overlooked by Mercedes, and subsequently Daimler/Chrysler ever since the first SLK came off the assembly line. Of course it shouldn't be there, especially after all these years. But it's simply a problem that Mercedes chose to ignore (probably for cost reasons) and we have the dubious honor of winding up with.
Remember, no car is perfect, no matter what the price.
At least the problem area on our cars is easy to get to, and not that hard to prevent, or repair, as long as it's addressed in a timely matter.
We've all been privy to some seldom seen photo's of a Crossfire "skinless" thanks to Andrew's posts of his car while it was in the body shop. Even though his car had the beginnings of the dreaded door gutter rust, the rest of his car looked remarkably clean. So I don't think we really have to worry very much about any other serious "problem" areas of corrosion. Well, probably no more than any other car.
I do wonder what the underside of the doors on the new SLK350's look like.

 

As far as I know Mercedes has numerous TSB's out on the rust issue that seems to be prevalent in the entire Mercedes line up. Chrysler however does not have any TSB's out...

I think the next time I by a Mercedes or Chrysler product will be 20 years from now, unless it was made from the mid 50's to the early 70's.

 

I currently have my Chrysler dealer working on my rust problem, Chrysler will be paying for the repair. I did go to see the autobody shop that will be doing the repair and I spoke in Depth with him. It seems he will be chemically treating the rust after he removes the paint and he will them repair only the area thats rusting. He will then blend the paint ONLY on the inside of the door where the rust is, and not onto the outside of the door. This will be better because I don't want to have a paint blend color issue on the outside of my doors. Hopefully this will fix the issue completely, and I won't have to worry about this issue again. Unfortunately this little repair will most likely show up on a Carfax about my vehicle, and may lessen the resale value of the car in the future, but I think its worth not having a rusty car. Any comments or suggestions ??? before I bring it in?

 

When you get it back, I would still coat the entire area with some sort of "sealant", like Por 15, or the Rust Bullet. You can even get Por 15 in clear so you won't see it.

 

When I said that Mercedes chose to ignore the problem, what I meant was, they didn't bother to redesign the rain gutter so it wouldn't continue to hold water. That's why it wound up on our cars.

 

I think most likely I will also apply the por 15, also with all my research (and I did a lot) The por 15 is a better product than the rust bullet. I'll let you guys know how everything turns out.

 

I won't be able to get to look until sometime this weekend, but are there drain holes in the door bottoms? Sounds like there are none. And if there are none, can we drill some small holes ourselves? Thanks for any reply.

 

there are plastic plugs in the door, I popped them out of my doors for better ventilation.

 

Andrew,

I like your idea of not sanding but the POR-15 "Directions for people who don't read directions" (see attached) item #10 states "POR-15 should not be applied over other paints".

At this point I don't have any rust, but everytime that I check under the weather-stripping it is wet. I washed my car on Sunday left it in the garage all week and on Thursday night when I pulled the weather-stripping it was still wet.

Any comments?

POR 15 directions.pdf

 

I just checked by door bottoms and found a little bit of bubbling, hey, it might even be some welding spots, very minor, no rust to see. Good idea about the plastic caps down below, removing them would create some better circulation. I hardly ever drive my toy cars in the rain or snow, so this should be a minor problem for me. It looks like I could drill some drain holes in the bottom, but I'm not sure they would be the VERY bottom, to get a good drain of water. It might cause more problems down the road later.

 

I think there is still a misunderstanding with some people as to what exactly the problem is, or how it is caused.
As long as the factory drains in the door are open, I don't think you have to remove the black plugs at the very bottom of the door. I don't think the doors themselves are holding any water. If they were, you would be able to hear the water sloshing around in the door every time you open it. Or see tell-tale signs of your doors "weeping" on your rocker panel.
What causes the rust to actually begin is water that is retained by the weather strip is being trapped against the small vertical section at the back of the trough that holds the weather strip. Unfortunately, this is exactly where two pieces of metal "overlap", and on the very edge of that overlapped metal is where the rust seems to start. Since it is a continuous seam, it's very likely that moisture seeps down in between these two pieces of overlapped metal, and eventually comes in contact with metal that has no or very little paint or primer, and the rust process begins to spread under the metal that is coated.
The real culprit is that exposed seam, and of course the fact that the weather-stripping shouldn't be retaining water in any location either.
If you can successfully "seal" that seam (well actually the entire gutter) then any water that lays there will be harmless. That's why I'm going to probably drill holes in the bottom of the trough to encourage and facilitate water drainage. Deciding just exactly what kind of paint sealant I'm going to use is the question.

 

This topic has been in my thoughts for a couple weeks now (and really bugging me). I got my "new" '05 a month or so ago and upon inspecting the channel at the bottom of the doors last week, I found some rust in that "overlapped" area on both doors. Regardless of what people are saying, this is not going to be an easy area to fix because of the lapped seam and the 1/2" area where there is no paint in between these welded/lapped parts. On my car, the seam is sealed on the bottom side from the factory with some type of seam sealer (helps hold the water in there...?!?). There is going to be moisture trapped between the overlapped parts unless you take a blow dryer or heat gun and dry out that area completely for a while prior to applying paint, POR-15, or some kind of sealer. I really like using POR-15 on rusted parts, but I believe that it's not a good thing to use over existing paint (the original paint will eventually bubble if there is any water/moisture getting in there or already there). At that point, the POR-15 is actually helping seal the water in instead of out. (POR-15 is only as good as the surface or paint it's being applied to, so over existing paint, it's not doing a whole lot).
I dried out the seam area with a light application of the heat gun for an hour or so. I spray painted the seam where it was necessary because of bare metal. I then applied 2 coats of auto body undercoat sealer with a brush over the seam area and any place else where the edges were unsealed. After and hour or so of drying, I re-inserted the rubber molding. I'm hoping that the flexible body sealer will do a good job of sealing this area from moisture, but won't know for sure until next spring when I check it again. Good luck you guys and thanks for posting this issue in the first place. A proven/quality repair could save more than a few doors...

 

I would definitely pick up one of those cheap sand blasters from Harbor Freight tools, load it full of grit and have at that nasty rust.

 

I think the Rust Bullet stuff may work better for this.
I would think the paint should be taken off in the areas and then treated/painted (no matter what product is used).

My neighbor was a Chrysler Service Manager a couple of years ago.
He said that Chrysler almost never covers rust under warranty unless it has created a hole from the inside to the outside.

Under warranty:
Has anyone had their doors replaced c/o this issue?
Anybody had their trunk or SRT6 wing replaced c/o this issue?

 

No, but they gave my that option. Replace both doors or fix the original doors.