I have had the car for a couple years and I can no longer take the rattle from the hatch. I have played with the rubber mount on the back but it didn't help at all...I can't even find out where it is coming from. It is not so much a squeaky rattle as it is a metal on metal rattle. Sounds kind of like the entire hatch is bouncing up and down...but when i lift up and down on the spoiler real hard it feels very secure.

Any ideas on where its coming from and how to fix it?

 

It could be a couple of things. First check your spare tire on the side, it may be loose. If not that it could be your exhaust pipe. When i got my headers put on not to long ago, one of my pipes started to make a squeeking noise. From that noise it sounded like my hatch was making it.

 

I have dumps off the headers half way back, no tips, and a N20 bottle now takes up the spare tire comparment. I tried taking the bottle out to see if that was it but it was still there.

 

It sounds to me that you have a high horsepower vehicle (Nitrous), it could be your frame is twisting if you do not have sub frame connectors.