I had an 1/8" aluminum skid plate lying around my garage (thanks previous owner) and used that for the brackets. I bought a couple 1"x1"x48" square steel tube from Home Depot to use as the crossbars. I wanted to use a 1" round tube, but could not find one in the big box stores... I left the bars their full length so there is some overhang off both sides.
Other parts needed:
8 - M6x1.0mm x 20mm bolts - these go into the mounting holes on the roof rails
8 - lock washers
8 - regular washers
4 - corner braces - secures the crossbars to the brackets
4 - self-tapping screws -secures crossbars to corner braces
4 - bolts and nuts (i think mine were 3/16" bolts) to secure the corner braces to the brackets
4 - Plastic Inside Furniture tips -http://www.lowes.com/pd_37856-37672-884 ... facetInfo= - to put in the ends of the tube
Initial sketch
The holes on the factory rails are about 5 7/8" apart, on both front and back sets of holes. I just held a piece of paper against the rail and punched the holes with the tip of a pencil. Then I just sketched the design above, giving about 1/4" around the holes and opening for the tube. I only had to design one bracket that works on the front and back. The front most and rear most mounting holes on the rails are 1/4" lower than the inner holes. The 'level' line was used to make the hole for the crossbar level. To install the bracket, put the lower hole (left hole in sketch) towards the front (if put on the front holes), or towards the back (if put on the back holes).
The roof rails are NOT parallel. The rear set of holes are about 37 3/4" apart (right side to left side), the front holes are about 39 1/4" apart (right side to left side). I found this out after I made both front and back rails. I just had to re-drill the holes for the brackets on the front crossbar.
Rough cut out of the bracket
Cut to shape and marked the holes to be drilled. The 4 marks on the top were used to cut the hole for the crossbar.
Holes drilled and cut out and burrs ground off.
Test fit. Looks good!
Everything installed!
View of the inside of the bracket. You can see where the corner brace goes.
Ready to go camping!!
I still need to paint everything, especially since I used steel tube instead of aluminum. I also still wouldn't put more than 100 lbs of stuff up top so there isn't too much stress on the rails. The setup seems to be pretty sturdy. I can pull on them and it shakes the whole car. They also seem to be pretty quiet. Up to 70 mph there is no noticeable noise, unless you vent the sunroof, then there is noise starting at 40 mph. A fairing may help with the noise.
Hope this helps you guys to design your own setup. Message me and I can send a PDF of my sketch. Let me know if you have any questions about my setup.