I have this problem going on too, one very similar to it. I took it in to my mechanic, just seeing that I had oil leaking under the car was enough for me to have him take a look at it. After the analysis my mechanic told me it was my rear main oil seal and to get to it would require dropping the tr...

No one knows what it is???

Oil pan leaking from black square plastic part, what is this part and is there a common problem with it like o-rings or seals?

Did you fill it with ATF or a quality Power Steering Fluid?