Looking good, man!!
I have added a couple of bags of gypsum to my surface, and WOW...what a difference. If your track doesn't hold moisture and is not packing into a good surface...Check out gypsum.
I got it at Menards (any lumberyard with a garden center) for about 4 bucks a 40 lb. bag. I spread it on with a lawn spreader and watered it in. It took a little while for it to work in, but now it is really nice. I used 80 lbs. in my little track, so you would prob need at least 5 or 6 bags to treat your track once. I also didn't apply mine evenly, so I have a little variety in surface.
Keep the dirt coming in...never enough, is there?