I have the factory crossbars with a pair of Rocky Mount Tie Rods. They fit the aero factory bars, are lockable, and IMHO are much better looking than the usual (and boring) Yakima/Thule designs. Plus you can get an array of colors.
I was concerned about the ease of removing the crossbars with a Torx wrench but the solder idea is BRILLIANT. I'm doing this tomorrow.