Version 1:
Using 1" square aluminum tubing, I bent a simple hoop that attached to the radiator support. This design was very simple to make but had some major issues. First being that if it was hit by something decently hard to break the bolts used to mount it, it would go right through my A/C condenser and radiator. The second issue was that since it was only mounted with two bolts and didn't have much surface area on the radiator support, it bounced a fair amount. It worked for the couple weeks I needed it for, but I took it off and came up with a new design. Pictures to come if I can find them.
Version 2:
I was looking to make a strong light bar/brush guard to protect my bumper from bottoming out. Steel was chosen for its strength and capabilities to be easily welded. My friend and I made a hoop that would mount underneath the car to the sub frame and was bent up in the front to get some height for the lights.
Plates were welded to the ends of the tubes for a flat surface to mount onto the sub frame and little extensions where added to reach up to the frame rail right under the bumper beam. It was painted with truck bed lining to resist rock chips.
This was a solid design, you could easily stand on it and it did protect my bumper several times from being totally destroyed. One time I put my tire into a sunken man hole cover right where a hill started and slammed the light bar into the ground hard enough to break the lights I had on it just from the shock. The tubing bent a little bit and the bar bent up, but it had saved my bumper cover and possibly my radiator support from any damage, very solid design.
I took it off after I hit the deer since I got a new bumper cover and the bent light bar rubbed on the bumper. The only issue was that it hung down lower so it ended up hitting driveways and such where the bumper usually wouldn't hit at all.
Version 3:
I was looking for something to get the lights a little higher and didn't have access to a welder so I decided go back to aluminum and mount it to the top of the radiator support and the licences plate screw holes (those holes can support a lot if loaded correctly) I wanted to make it wider for more lights, but I used part of that aluminum piece for something else and I only had one set of hella 500's. The bar is pretty ridged up and down and side to side, but the lights rotate up and down a bit.