I'm excited to share that I think I've stopped the clicking noise! I took the side panel off (the one that has the power seat controls) to get a closer look at everything. I sprayed more white lithium grease on every joint I could find, but what I think fixed it was I tightened up several bolts. When I moved the seat bottom with my hand and looked under I could see the joint where the arrow is in the attached photo was making some noise, almost like the clicking noise I've been hearing. So I tightened the crap out of that bolt, which you cannot see the head to but it is a T-40 Torx bolt. You have to move the seat up some to be able to fit a socket/wrench in there but I was able to get it tightened up. There's another one on the back side too, and I went ahead and tightened that up too. There are 4 other large T-45 bolts that I snugged up as well I pointed to in blue, but they didn't move much at all (well I only got two of them because the console is in the way). There were also a few other torx bolts I snugged up, that you can see in yellow arrows.
So between that and the grease, I think I solved it, since I did my usual 25 mile drive to work with no clicking!!!
Going to look into this now. Mine's been clicking since shortly after I bought it, but of course the techs were never able to reproduce it (sigh). Told them multiple times where the noise was coming from and even referenced this thread, but of course they wouldn't take a look unless they could reproduce the noise.
If this fixes it for me, I'll be printing out the thread and serving it with a little crow to the techs at my dealership, lol. It's funny how sometimes they won't listen to the collective knowledge and experience of thousands of owners of the specific vehicle you have.....
Current: 2016 WK2 Overland 5.7L, 2017 MP Compass Latitude
Previous: '99 WJ Limited 4.7L