[ThisSuckersElectrical]

That would be coming from inside the transaxle. Put it in run the pop the hood to start the ICE. I am sure you will hear it coming from the transaxle.

 

[ThisSuckersElectrical]

You can clearly hear the rattle at 25 sec in, after the ICE start revs decline a bit on this cold start.

The second clip is the same sound from inside the cabin driving, just the two thumps I could catch at the very start. Hearing it from inside can be rather tricky.

https://soundcloud.com/rorohello%2Fsets%2Fcar-rattles

My 2021 did that day one on delivery. It stopped after I had the PCM, HCP, and AHCP software updated.