Of course, at some point in the 2000s a designer at #renault decided that a flat roof rack is practical but not looking nice. So they curved it by 15mm (7.5mm on each side). My "new" 1983 vintage roof box is not curved on the bottom side. It got steel tubing and a sturdy zigzag pattern on the bottom. It. Will. Not. Bend. And that's fine. So to mount it in 2026 I need spacers. And as we live in the future™ now I just fired up #freecad and let the #3dprinter do the work. This is no shiny fancy thing, just a wedge with a hole. But in 2026 it just makes sense to let the machines do the job - I would not be faster/better if I started to cut and grind plastic or wood. Tested at up to 130 km/h the roof box is nice: nearly no sound, just a silent "sssshhh" wind noise, and its not noticeable regarding driving dynamics at least in empty state. and the whole thing is just 2m tall.