The description that follows is from FormerFF
It has four crossbars, and is about 15 feet in length. The two that are farthest apart span a little more than four feet.
When the gliders are off, I can remove two clevis pins and drop the rear supports, then swing the back of the rack up and open the hatch.
There's a bumper support about six inches behind the front bumper. I built two brackets that are shaped like the letter "I", with a piece of 1/8th inch plate on top, 1 1/4 inch square tube on the bottom facing forward, and a section of 1 inch square tubing connecting them. I drilled two holes on each side to attach the bracket, and bolted it onto the bumper support. When the rack is to be attached to the car, I insert a piece of 1inch square tube into the 1 1/4 square tube on the bracket, and hold it in place with a clevis pin. This 1 inch square tube holds up the front vertical support.
The one Achilles heel of this rack is that the pieces of square tubing that stick out of the front of the car will ground on some very steep driveways. It's never a problem on the road, but if I see a driveway where cars have been scraping, I have to be very careful. If you can get the brackets that stick out from the grille, that's a good idea. When I get a chance, I'm going to redo the front brackets so that they angle up, and that will solve the problem.
One of the reasons that I have the front support tied into the roof bar is the relative weakness of the front attach point. While the bumper support is plenty strong to handle the vertical load from the front support, if it had to handle the bending load that a freestanding goalpost setup would induce, I'd be less confident in its ability to do so. Another positive about tying it all together is that it is somewhat failure tolerant. One time I had the roof rack attach points lose their hold on the doorframe while on the highway. The only thing that happened was that the entire assembly slid back about an inch and a half. I didn't even notice a problem until I stopped.