When parked and on a cold start early morning, I hear a sputtering noise underneath the car in front of or near differential on a w213 2020 e350 4Matic. Any idea what it maybe? Attached video with sound.

That is indeed very strange.

OP, did you ever figure it out, that is strange noise

it’s condensation related. Only happened on cold mornings during winter months. Nothing heard till date since the weather warmed up.

Interesting, thanks for the update.

You might have something loose underneath which cause the rattle before it settles.

Time to get a pair of chassis ears out and listen for it then.