I already have a full Yakima system I used on my Xterra - two crossbars, two sets of kayaks racks (mako saddle, hully roller), two bike trays, and four lowriders to attach to the factory rack. I'm thinking the Vibe's factory rack isn't up t the task. I do have a kayak trailer, so I could only haul mountain bikes on the rack if necessary.What what's the best way to attach to the Vibe's roof?The bike trays look like these:lowriders: