Can anyone identify these squeaks?

[4cylinder]

This is a bizarre problem that acts only during the summer and only if the car has been parked in the hot sun in temperatures of at least high 70s F. If it's a cool day or if I parked in the shade, then I won't hear the noise.

 

When I go over cracks/bumps at low speeds, I can hear a loud squeak that sounds like plastic-on-plastic or plastic-on-metal. This is quite distinct from the normal interior creaking noises one can expect from any car that's been subject to hot weather. I don't hear the noise at freeway speeds, but I suspect that's only because it's masked by wind noise.

 

Obviously this has to be something that's capable of expanding when subject to the sun's heat.

 

I actually tried taking it to the stealership at the end of last summer and while they confirmed the sound was a problem, they said it was a "nuisance issue rather than a safety issue" and since I was about to leave on a road trip, I just took the car back. Unfortunately the temperatures dropped just as I finished my trip so I couldn't reproduce the sound anymore.

 

Now I actually have some free time and it's still pretty hot outside in Michigan. However I don't trust the incompetent stealership staff to identify this on their own, so I'm wondering if any experts here can chime in. Could it be coming from the shocks/suspension springs? I think the sound originates from around the footwell which is why my theory is the shocks/spring. I also had a bad 2018 when it came to pothole collisions and it's not unlikely that something got misaligned as a result.

 

Here are 4 videos showing what I describe. The descriptions in each video mark the timestamp at which the sound is most audible. Sorry I don't have the best phone out there for this so the squeaks don't sound as bad as they do in real life.

 

 

Thanks in advance!

[CaliGiant]

I don't know if its your problem or not but I had a loose top mounting nut on one of my rear shocks. It would pop or click every time i went over a bump and was tough to tell where it was coming from. Because it almost sounded like it was coming from inside the car or trunk. When i found it I could literally twist the top of the shock and nut with my fingers. I figured it was the shocks and mounts so I ordered $300 worth of parts for both sides since I figured i had 170k miles and the weight of that heavy battery back there must be wearing those out. Shocks were like $70 each and mounts were like $60 or so. After I took it apart I found out that it was a loose nut from the factory. I could have just tightened it with a wrench on the nut and vice grips to hold the top of the shock that is above the mount. I ended up just replacing the shocks anyway but the funny thing is the factory mounts that were 7 or 8 years old and had 170k miles were actually stronger than the replacements. I could have fixed it in 3 minutes. I've read other places that the factory in Mexico has had issues with tightening bolts down to specs. Another place that has had issues was the bolts not being torqued correctly on the engine and between the motor and tranny.