At 63k on an ex-rental I would probably not do a flush. My cd4e first started shifting funky after a flush at 60k. I am the second owner so I don't think that fluid had ever been changed before. That flush, among other things, probably contributed to the problem I'm having now.

IMHO, you should probably have it drained and filled a few times. Have it done once, drive it for a week or so....then have it done again.....and again if you want.Good luck.