2005 grand prix....coolant loss, but not a leak that is visible, with a transaxle oil loss (no oil at the bottom of the dipstick),pulling the engine oil dipstick, overfilled engine by a quart or so.

First, don't overfill motor oil. If overfilled too much, the crank will dip in to it and whip it in to a foam like a blender,..= no oil pressure.. Check transmission running, at operating temp, in Park. (No offense, some people don't know that) At 180k, you will burn some oil from worn rings, but if it's not blowing blue smoke, no worries. just keep at proper level. And loosing a small amount of coolant, same, no worries. Now the transaxle, good question, if there are no spots in your parking place ....that idk.