First the observations, then the question...
Note: I've gone through all this trouble due to a subwoofer rattle.

2month old CTS, Rear decklid and C-Pillar Covers:

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So I followed the directions posted by CTSVett for removing the rear decklid and accessing the subwoofer.

First instruction, "remove little 'AirBag' Screw cover, be careful not to break tabs off cover". The tabs on one cover were already broken.

Second, "use 7mm nut driver to remove the screw holding in each C-pillar cover". Both covers had broken plastic 'screw tab/brackets' and were only being held in by other moulding, not the screws.

Third, "remove upholstry clip from each side of the front of the decklid to remove". One of the clips was missing/never installed.

Fourth, there is a large plastic bracket attached to each side of the decklid used for lining up and retaining. One of these had fallen off inside the deck and was loose floating. This was not the cause of the rattle.

After removing the decklid, I determined the rattle was coming from the plastic subwoofer 'bracket' thats mounted to the steel deck. Cadillac informed me there is a TSB and will be replacing the bracket (with a better one?). If their bracket doesnt work, I know Dynamat will.

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Heres the question. How do I complain to Cadillac about the broken mounting points and poor installation of rear deck. Do my actions in removing the hardware myself relieve them of any responsibility? Obviously they wont know I did it unless I tell them. The C-pillar covers will need to be replaced, there is no way to repair the broken tabs. As I said, this car is 2 months old, anything that I found wrong in the rear deck was like that when I got it. If I dont want to tell them that I took it all apart, how do I explain discovering these install flaws?

Thanks for any help.

BTW, CTSVett's instructions are clear and to the point, the removal procedure was basic and took under 15 minutes.

First the observations, then the question...
Note: I've gone through all this trouble due to a subwoofer rattle.

2month old CTS, Rear decklid and C-Pillar Covers:

-----------
So I followed the directions posted by CTSVett for removing the rear decklid and accessing the subwoofer.

First instruction, "remove little 'AirBag' Screw cover, be careful not to break tabs off cover". The tabs on one cover were already broken.

Second, "use 7mm nut driver to remove the screw holding in each C-pillar cover". Both covers had broken plastic 'screw tab/brackets' and were only being held in by other moulding, not the screws.

Third, "remove upholstry clip from each side of the front of the decklid to remove". One of the clips was missing/never installed.

Fourth, there is a large plastic bracket attached to each side of the decklid used for lining up and retaining. One of these had fallen off inside the deck and was loose floating. This was not the cause of the rattle.

After removing the decklid, I determined the rattle was coming from the plastic subwoofer 'bracket' thats mounted to the steel deck. Cadillac informed me there is a TSB and will be replacing the bracket (with a better one?). If their bracket doesnt work, I know Dynamat will.

-----------
Heres the question. How do I complain to Cadillac about the broken mounting points and poor installation of rear deck. Do my actions in removing the hardware myself relieve them of any responsibility? Obviously they wont know I did it unless I tell them. The C-pillar covers will need to be replaced, there is no way to repair the broken tabs. As I said, this car is 2 months old, anything that I found wrong in the rear deck was like that when I got it. If I dont want to tell them that I took it all apart, how do I explain discovering these install flaws?

Thanks for any help.

BTW, CTSVett's instructions are clear and to the point, the removal procedure was basic and took under 15 minutes.
It sounds like this was a warranty item to begin with, you should have let them do the maintenance themselves under the TSB... :(

not very helpful....

You wanted an answer.
Things that are under warranty should be taken care of at the dealership. One of the things that service departments despise the most are 'backyard mechanics' trying to fix things themselves and only making situations worse.

You could try to put it back together with little evidence that you tore it apart and complain that the deck rattles to the dealership. If there is any evidence of tampering, it will not be covered under warranty.

Not trying to sound harsh, but that is how the dealership is going to look at it.

Thanks for the clarification. No harshness perceived. I tore into the rear deck out of my own curiosity, and reconnaissance. As I plan on upgrading the sub in the near future, I was curious to see what was going on back there anyways. Im quite a bit more skilled then a backyard mechanic, and as I made no attempt to fix anything, there is no evidence of my tampering. As you and others have suggested to me, I have no choice but to go through the pain in the rear procedure of complaining till they get it right. Its very frustrating since I know exactly what is wrong, and what I want done, but cant come straight out with it for fear of being held responsible. I've just learned a valuable lesson about the paradoxes of owning a new car.