2011 P4X with 203,000 miles on it, not having any “real” issues with it but it gets a slip every now and then if the fluid is hot & driving on the highway and have to kick it down to pass or whatever. I have drained the little pan (2 or 3 quarts) & put the same amount- yes, the correct fluid-, back in several times since I have owned it. I would just feel better if I added something good for high mileage transmissions. No leaks or anything. Any recommendations?