I found a sedan photo showing the cover plate that needs to be removed on the engine oil pan. Mind you, I do not have an automatic G so I can't say how this will be different on yours. There must be some better dust/water-proofing.
It sounds like you must have lowered the tail housing of your trans and slid it rearward to clear the torque converter while still attached. You're going to have to get it back in again so be sure you know how to do it now, before you get stuck later on.