O.K., I have received assurances from A.R.E. that the Z series won't interfere unduly with the utility track. It mounts with 4 clamps, one at each corner, so you are losing maybe 1 or 2 inches of travel at each end of the tracks. Also, you may need to take off the rear clamps (easy to do) to remove the sliding bed extender or bed divider. The dealer said that he could eliminate the clamps by drilling and bolting, but he didn't recommend that.
I placed the order for the Z-series with liner, remote lock, tilt out front window, clothes hanger, 12V light, & roof rack, installed for $1745, ETA mid to late May. The mold is supposed to be finished mid-April, and they are already taking orders, so the waiting list is growing. I went with a dealer-installed Yakima rack rather than the factory A.R.E. rack as it had more flexibility on the various attachments. You can take the rack off when not in use, and leave only the rails, which don't stick up vertically very far, maybe 1/4 inch. The Z-series is cab high, the rack sticks up 5 inches, and the attachments project further above the rack, depending on what attachment(s) you select. So if you have a standard 7 foot garage door, you can probably get in the garage with the rack on, but perhaps not the attachments.