There's many different varieties but all consist of taking some kind of on the cheap shelving from Lowes or Home Depot and mounting them in the rear cargo area suspended from the factory gear hooks. I've studied up a bit on the variety of methods and wasn't impressed with the velcro straps being used or the rattley carbiners. I found one guy who went to Home Depot as I like to do and wander around looking for what could work if rigged together.
Maybe the other hatchbacks can utilize this info as well.

So for the supply list it goes like this
- 4ft long storage shelf
- 2 1/4 x 4" 6mm thread eye bolts
- 2 sets of 1/4" washers, lock washers, and nuts
- 2 Sliding screen door rollers (B551)
- 2 1" lashing buckle straps (Walmart/REI camping section)
This should put your total under $20

For my shelf I got the Closet Maid 4" x 15.89" gray one that matched my interior from Lowes. They used to manufacture a double lipped shelf hanging shelf that worked well for keeping gear from sliding out frontwards or backwards but it's not made anymore so I made my own lip.

I used clamps, two pieces of lumber, and a dead-blow hammer for my creation. I gave it just a little more lip than the other side while keeping it the right width to fit inside the X. Just work it slowly down the line and back.

Now the fun ghetto fabbing came. Take the eyebolts and open them up some in a bench vice.

Insert the plastic rollers and close back up with the vice

It was necessary for me to trim one wire off each side of front of the shelf to allow it to fit between my roof mounting points. It was also necessary for me to trim about an inch off one of the "studs" to fit them in between as well.

After the cuts with my dremmel I smoothed down the burr and tack weld left.
Then the fabbed swing mounts just slide on.

The directions now call for your eyebolts to be mounted. From my reading, eyebolts come in standard, while the roof gear hook screws are metric. I read that you could encourage them in just fine anyway. This would enable you to put back on the factory hooks and the pretty trim to look nice. I had trouble with the encouraging.
I found that using a starter bolt helps keep from jacking up the eyebolt threads. Unfortunately I didn't think to use a grade 8 bolt so while I was able to slowly ratchet the standard 1/4" into the metric hole, my strong like bull muscles ended up breaking the bolt off in the roof. With no part showing enough to try pliers, I called it quits for the night knowing I'd have to explore other options. There was a free hole next to the factory welded nut but the metal was too thin to hold much and there was no way to get behind it to put a nut on without removing the roof.
The next day I did the Home Depot walk until I landed on some of the automotive speed nuts and bought one to fit 1/4" - 20.
Then knowing the interior trim would hide my surgery, I plan B'd it, took the dremmel, cut a slit near the thin hole and hammer slid it in to place. That worked like a charm and it felt good double middle fingering the broken bolt afterwards in celebration of my win.

I put all the trim back together, installed the eye bolts including a washer, lock washer, nut combo to lock it down and then slid the rack into the rollers.

The great thing about this method of securing the front is that if the rear is mounted with a quick release method, the whole unit hinges down allowing easy access to stored items.
The buckle strapping worked great lashed around the rack back up to the other gear hooks.

I'll trim up the excess nylon strap and take a few more pics with some cooler gear on it, but you get the point. I've seen inverters bolted on underneath, tons of stuff strapped securely on top and a bungee method of hanging a paper towel roll off of it. I was thinking at least no more mushed hot dogs, bread or maps too :)