I bought mine from justforjeeps - - just installed them. As has been said elsewhere on this site, NOT a five-minute job, but if I had been a little less "type-A," it probably would have taken ten. I installed the front bar as far forward as possible, and left 21" inches of clearance between the open tailgate and the back bar. That leaves about a 27" spread, which I'm hoping will be enough for a Thule 686 or 687. (I have an email out to them, but if anyone has real life experience, I'd love to hear it!)
A few observations about installing the rack. Yes, loosen the top screws to drop the mounting bracket, but if you loosen them TOO much, the inner lock nut will not catch! So I'd suggest dropping them JUST enough to fit into the tracks.
Also, the paper instructions don't explain the "locking" mechanism. After you install the rack, you must unlock one of the end caps and slide the rubber stripping across the length of the rack -- then replace the end cap and lock. Not the best security, as anyone could slice the rubber stripping to get at the screws, but better than nothing, I suppose.