Alright..... I just installed 2 12s in the trunk and spent about two hours isolating rattles and using foam padding to stretch or cushion the contact areas that were causing the rattle in the rear deck. (trunk still rattles like a **** from the outside but that's another story) Already put foam on the inside of the license plate to prevent that from sounding super ghetto.
I threw in my Bass test Cd's to isolate rattles at different frequencies and found that the covers to the rear seat belt mechanisms located on the rear deck rattle at frequencies around 60hz...... I suppose I could take the covers off but I'm sondering if there's anything else I could do. (I already took the plastic covers off the child seat hooks... they were the first thing to go). So that's what I'm left with for interior rattles.
Now as far as exterior rattles I know dnamat is the only option. Is there anything else that I can do that doesn' weigh as much that would quiet exterior rattles? I know this is the 5th Gen forum but I figure that the 60hz rattle for the seat belt mechanism cover was 5th gen specific. Anyone else with experience getting rid of rattles in the trunk of the 5th gen without dynamat........ If dynamat's my only option I want to use as little as possible..... That stuff's heavy.

Thanks

 

How about using the spray foam that expands on contact. The stuff they use in new home building. Spray some under the plastic cover and cross your fingers.

 

Yes, spray foam works good for the areas you cannot get to. I also added two more screws to my license plate in the back. That got rid of ALL the ghetto vibrations. I also added LRF (little rubber feet) to the inside tab of the side markers. They used to rattle like a **** on ANYTHING between 60-100mHz. The rest of the back I filled with Dacron from a linen store. It is lightweight and helps pad everything quite nicely. You can even use it under the plastic caps so they stay nice and secure.

Lastly, I cut a hole where the Bose system goes to vent the wave off the back window. Then, covered it with a custom grill. That eliminated pretty much all the remaining vibrations. Well, except the little stuff here and there I’ve never been able to isolate.


ADMAN

 

YeahI didn't have the bose sytem so I don't have a pass through. I'll probably put on a custom grill.... As far as from the outside.... I think my rear sidemarkers are one of the culprits. I can't isolate it though. It sounds like there may be something from inside the trunk as well. metal to metal I believe. I've already isolated the trunk spring rods and they no longer rattle..... You think the grill will help with the rear deck vibrations thus minimizing the rattle from the seatbelt mechanism covers. 2 Rockford Fosgate he2 12's powered by a 200 watt by 2 bridged MTX amp pushing about 400 wats per speaker..... I think I'm gonna go ahead and dynamat the rear metal panel just underneath the rear package shelf. That seems to have a resonant frequency right at 60hz.....
Another question. Does your car rattle from the outside? I admit my speakers are freaking loud and there may not be a way around it from the outside without dynamat.... I really want to explore every possibility before I do. Oh yeah... the foam padding on the back of the license plate worked wonders...... But I'll try filling the space between te trunk lining and the sheetmetal with dacron like you suggested.. I can't imagine it weighing too much and it sounds like it will help get rid of the plastic to metal rattle.