Bought a JSW with 68k on it. One owner dealer serviced. They said they "serviced" it. Could not prove transmission fluid was changed. I finally changed it at 92k. Several pan bolts had the heads rusted off and one snapped. Drain plug had to come out with vise grips because the hex was rusted out. Fluid was BLACK, magnets were hairy and the filter looked like it had been dipped in tar. I installed a new filter, drilled out the bolt and replaced the bolts. Changed the fluid using the Idemitsu fluid recommended by oilhammer. I changed it and drove it a few days and changed it again to double check the level and get more old fluid out. All in all I ran probably 8 quarts through it and when I checked the level the second time it came out almost red colored and transparent. Here is the point of this story, the way the car shifted after the second change was amazing. It downshifts and upshifts crisply now instead of being sluggish, so if you have an auto tranny with old fluid, get it out of there. Another interesting anecdote, I called my local dealer to buy some new pan bolts. They said "we don't stock those because we never change the fluid".