Excellent approach to longevity.
My old '99 has had different fluid changed when I remember it, but I had dealer flush my tranny fluid early and had a new screw-on filter (rated for lifetime, do not replace) at 25,000 just because I wanted to take care of my new car. Dealer couldn't believe it. Since then tranny fluid serviced early as regular maintenance item.
Now, at 231,000 miles, that tranny is the most solid thing on the car. My car diff's don't complain. T'wer me, thinking I'd re-prioritze my spare money, because diff's are pretty tough.
