This is simply the profile of the 2010-2019 (I think they're all the same, mine is a 2018) Toyota Sienna factory roof rail. I want to mount something to it, so I need to know the shape.
WARNING: 3D Printed stuff isn't necessarily strong, particularly with loads at highway speeds, so whatever you're doing with this, please make sure it's secured appropriately. It'd really suck to accidentally kill the driver behind you.
Note: The intent here is to provide the inner curve. On my vehicle it's a little skinny on the bottom, but with the small test print a little weight made it fit perfectly, so I'm calling it good. For the final one I might print a TPU section near the rail with an ABS housing so that it can press a little more dynamically on the bottom.
Presumably you'd want to print it bigger with an appropriate attachment point or feature on it. And presumably you'd need a way to strap it down (I'm planning on industrial Velcro for my application, maybe a clamp).
Full disclosure: Gearbest gave me the CR-10 that I printed this with, so I feel sort of obligated to put it through it's paces.