I have a 2002 mustang gt, automatic, 116,000 miles, and it has a very small leak, about the size of a dime, of transmission fluid, when it sits. Doesn't leak when it runs. I believe its coming from where the torque converter is. It seems to be coming from where the black plastic piece is on the bottom of converter. Not sure if this is a plug or what? It shifts fine, I have noticied it shift rough sometimes when going into overdrive, very rarely though. I have had the fluid flushed before, but should I get the fluid flushed and the gasket and filter changed? Every automotive place tells me to get a new transmission. I don't drive it often, just for fun, but want to make sure, on what i need to do. By the way, I do need to flush it again though, because the fluid is very dirty. Could be oil too, not for sure due to the tranny fluid being dirty also. Will smell it when leaks again. Thanks so much!