Rear Suspension Noise when cold outside - '09 M45

[dback]

Hi everyone - Hoping you all can help with my issue.

2009 M45x
99K miles

I have owned this car for the last 3 years and over that time it has developed a squeak in the rear suspension on cool days. It seems at it's worst on cold damp mornings after sitting in the garage. In an attempt to fix this, I have changed the rear shocks and stabilizer bar bushings. I have also sprayed the rubber bushings with lithium numerous times. This has had no effect on the noise. I have also removed the spare tire and all of the trim in the trunk to rule that out. No change. When it is warm outside there is no sound and it rides great.

Here is a youtube video of the noise (don't mind the dirty seats). It is the scrunching sound.
https://youtu.be/2Rtk8OEpSXY

What could I be missing?

How do I rule things out?
If I were to start replacing things, would this seem like a logical order.
-stabilizer bar end links??
-upper and lower spring mounts??
-control arm bushings (are these replaceable without replacing the whole control arm?)
-what else?

I do not have a relationship with a local shop, so I would have to start from scratch there. Would you recommend just a general auto service shop or one that specializes in suspension work (do those exist)?

Thanks for your help - getting desperate.

[lexcrob]

I watched the video and heard a clunky type sound the whole time no squeak or any high pitch sounds. Honestly id say bring it to a good alignment shop. If anything the problem could shop up on an alignment. If it was a control arm bushing at least.

Id get physical with the car jump on it. Open a door and shake it really hard. Lay under it and get eyes on the noise.

The more you narrow the noise the faster someone can find it for money. At least thats my advice finding rattles for years at the dealerships.

[EdBwoy]

Like lexcrob, I'd recommend heading to a suspension shop. I haven't seen an alignment-only shop, but usually as I've relocated a few times I've found that most shops will refer you to a shop that is better with suspensions. Or dealerships, in my experience they have the best/newest in alignment equipment in the places I've lived.

I however, couldn't make out the sound clearly from the seat. If you still have time, try placing the phone in the trunk or on the rear parcel shelf to isolate noises from those areas.

Edit: Also, grab the end of the mufflers and give them a jiggle, to see if the exhaust system makes any such sounds.