people usually complain of atf on the floor. This occurs when it gets severe. Also, depending on how much fluid has oozed out, you may have shift problems. I have "heard" of control module failures due to the ATF shorting out the module. It's hard to imagine fluid going up against gravity and dumping in the module. The eaisest way to detect it is checking the car's belly when it's on a lift. You will usually see a oily spot on the front right corner of the ATF pan.