Foot off of the gas pedal you hear a clunk?

Yes a worn out transmission mount can clunk like that and can acually change the way the car drives but somtimes you get so used to it that you dont realize the effects of it till you change it and everythings tight again ...
Most times theyre pretty easy to change ..good luck hope this helps

some videos attached. I don't think anything is loose or show to be defective, but maybe am mistaken

It had ti tell in the video but it acually looks pretty good down there have you checked the exhuast somtimes it will briefly bump the bottom of the car somwher along the way id say look to see where the pipe runs if anything is close enough to it where it migh bump when slowing down or speeding up usually if anything is w8thing maybe 1 inch of the pipe there potential for it to swing over and bump the car seems to be in pretty good condition so that acually makes it a little harder to find it. good luck let us know what you find

I will check. Also, do these have center support bearing for the driveshaft? ya it is very clean, zero leaks too....

Attached. I will deive it again and check but am sure the clunking is mostly obvious when say driving in 3rd gear rpm at 3k and let off throttle that is when i hear it

Yeah 3 gear has alit of torque so it probably is the only gear that able to tweek it enough to do it also look near the firewall in the engine bay ti see what the closest part to it is and how far if its under an inch anywhere you getting close same with the all other components transmission engine rear dif all components usually if you see any under an inch away from bumping anything else youre getting worm luck it only does it once in a while a d you know when it will that helps alot also try to isolate where ont the car it coming from the front back left right sides youre on the right track I bet youl find it soon if not it might be a good idea to get it up on a lift with a good light it helps alot most times it reveals things you never knew about the car hope this helps

does the car has a bushing to some type of cross member?

Yes, it can be the driveshaft center support, can I ask where the noise comes from, the front, middle or rear of the car?

I already checked on the center support bearing. Everything looks clean and not cracked and no play in the driveshaft. It is from under the car. Something is moving. It is similar to a bad mount noise only when driving and you let go off of the gas ? pedal, i would say from middle to front

Okay, I would use a hydraulic jack under the oil pan on a piece of wood to try to lift the engine to see if the engine mount has separated. Do the same for the transmission mount.