probly was a leaky tranny before? then tranny has some dmg done already. nothing will fix it cept for rebuild or replace......
when did you get the car? if you are not the first owner, you dont know if the tranny leaked oil before. sounds like it did. oil pan leak so common.
i wouldnt rebuild it. at least wait till it dies to rebuild. i doubt it will die. just not smooth. to save some $ i guess u just deal with it. its 160k anywayz. drive 1 or 2 more years then replace the car.