That's exactly what the bar is for. Just swings down and sets onto the base just above the cushion. The spare tire thing might work, but I have the spare on the factory mount right now. One of the next things I'm looking at is a rear bumper/swing out carrier that will be more sturdy. I have someone who does fabrication, and I was considering a small ladder of sorts mounted to the swing out carrier that would be better than clambering over the tire...
In most instances I prefer to cook away from my vehicle. I also like to be able to remove what I'm carrying, but still be able to use it in place. I found a 45 gallon "Power Packer" storage box at Home Depot - $50. It carries my stove, cooking equipment, and various assundries. It also doubles as a table w/built in cup holders in the top. Very sturdy, inexpensive, and I can lock it when I put it out in the bear locker, or when it's just riding around in the back of my Jeep.
Yes, you can take it off just like any other top. You might want to set up a good "lift" system - places like Quadratec sell them - as the 200 or so lbs. is a little much for a couple of people like the stock top.
I had mine installed with the Yakima tracks. The front bases are in a fixed position as they are incorporated into the "pop up" mechanism attachment points. The rear bases are in tracks and have about 3 feet of adjustability, or you could put in a third set of bases to have three support bars.
