Yes, there is a way to do it, and I am about halfway through the process of making my own. When I get it done I will post links to some pictures. I might have just bought one, but I have recently spent so much money on mapping and accessories for a GPS that the GF gave me for my birthday that I wanted to try making one. I have spent a lot of time considering the options and after discarding several more complex ideas, came up with something that I think will be simple and effective. I won't know how well it works until I have it mounted and the lights running at night, but when I do, I will let you guys know.
Here's the basic idea: Use u-bolts to affix the short end of two separate pieces of 1/8" x 1" L-shaped bar stock to the subframe just aft of the oil cooler, one on each side of the bike. The long end of the L projects out the full distance needed to mount the lights. If I recall correctly, the short end was maybe 3.5" long and the long end was maybe 5.5" long. A third piece of AL, this one also 1" across and about 23" long, but in an angle form with a 1/4" angled part for strength runs across under the whole width of the L parts and is bolted to both of them, thus providing strength.
I am mounting Hella FF50s to this arrangement within a week, and will report back. The only issue that I can imagine is if the u-bolts don't provide enough resistance to rotation of the L brackets, in which case a single 1" wide stabiliser strap can run back to the lower rear part of the subframe under the removeable side pieces where there is an unused mounting point conveniently located.