I have a similar issue. Originally had the 30" bar mounted to a couple of aluminum collars on the roll bar, then added the roof. I also have a windshield and I am at the point where the light bar doesnt work with the roof and windshield on. Really want to avoid having the bar on top of the roof because it is not protected from branches and other obstructions up there.
Was thinking about making some aluminum mounts to put it just in front of the windshield but haven't gotten that far yet.