I just inherited my wife's Vibe to use as a work vehicle, for limited handyman work. I need a roof rack. I have some old Thule bars. So I got some hardware and a drill and attached them. There's just enough room at the front of the rack to fit a 1/4" hex nut and tighten it with a open-end wrench. I drilled 5/16" holes in the bars and racks, which gave plenty of tolerance to fit with somewhat careful measurements. The bolts are 2" carriage bolts, exactly the right length. They're 50" long bars, so I can carry a little lumber or drywall (with the antenna unscrewed).
I found out today I also need to get a rubber mat for the back deck. Toolboxes are heavy and they slide around too much.