Looking at the Yakima installation instructions it is not necessary to remove the headliner, just “be careful not to drill more than ¼ inch” into the roof. Not having to futz with removing and reinstalling the headliner is good news. Maybe.
And I expect that if folks using the Yakima rail system had inadvertently drilled through wiring harnesses in the roof there would be some hue and cry of caution. So good news there as well. Probably.
My primary concern would be the strength of the metal roof alone, securing the rails to thin sheet metal without knowing that I had positioned the holes to bolt through some structural brace or pillar, or had removed the headliner and added something to help spread the load.
I often have two canoes on a roof rack, and sometimes more. Even so I am less concerned about the stated weight limit of the rack than I am about how sturdily it will resist the sheer forces of a 16 foot canoe at highway speed, or in crosswinds, or in a sudden stop.
Having a bike, surfboard, skis or even a rocket box storage bin up there is one thing, having the mass of a big open canoe perched on the crossbars is another. Stick your hand out the window at 70 mph, then hold out an empty plastic cup. Yikes.
Still, if adding the Yakima rails is the only way to attach a convenient roof rack system to the van I’d probably cross my fingers, gather my courage and oh so carefully drill some holes in the roof.
Our truck, van and both of my son’s cars all have roof racks that will accommodate two canoes, which makes setting our own shuttles easy. It is also invaluable on group trips, where not being able to tote an extra boat is somewhere between unhelpful and shortsighted.
If you go the Yakima rail route and sometimes carry two canoes I would use crossbars wide enough to leave some air gap between the hulls.
This ()_() would be preferable to this ()(). I have driven into some hefty headwinds at highway speed with boats on the rack. At 70 mph + 30 mph headwinds there is a hurricane of 100 MPH wind being dammed up between two hulls, and a lot of lateral force pushing the boats apart.
Is the missus on board with the plan? When I came home in 2000 with a brand new Ford E-150 van and immediately drilled holes in the front bumper for bowline eye bolts there was some consternation.
How do you feel about pulling a small trailer?