Rear deck vibrations and dash rattles.

So, after a year of owner ship i have 2 gripes with my 09' spec.b

1. In the winter (avg temp of -35C) the dash makes a lot of noise. All the panels make some squeak or creak. Guessing it is due to just the shear temperature. My 00' legacy doesn't do this however. So its still a disappointment.

2. The rear deck with the harmon/kardon subwoofer makes tonnes of rattles at any level of bass. Bass settings at 0 and when mostly anything plays on the radio you can still hear it vibrate.

So, is there anyway to solve at least one of these problems. Hoping to solve the subwoofer rattle more than anything. I've tried searching but found nothing. Maybe i just haven't used the right terms.

TL:DR

Dash rattles in cold. Not a big deal. Tips appreciated.

Subwoofer in rear deck(behind back seats) rattles the entire deck. Lookng for solution to fix. Search turned up nothing.

for the sub rattles, you will find it's either the parcel tray trim rattling or the rear brake light housing vibrating against the rear window. For the trim, remove it, line it with some sound deadening material to increase it's mass and you should find it resolves the rattles.

For the brake light, use some weather stripping, the stuff you stick to the underside of doors to stop wind/water coming in under the door to adhere to the light between it and the window. Of all the Gen 4 sedans I've worked in, this was the issue 99% of the time.

As for the dash, apart from taking it apart piece by piece and using some adhesive rubber strips at each point the dash trim meets there's probably not a lot you can do about it. Personally, I would go to those lengths and am about to with my GenV.