Thule 598 Bike Roof Rack not Fitting!

Machined some t-slot nuts for my Thule roof rack! thule t slot rack T-slot for easy accessory installs; Upper T-track with QuickAccess interface With a roof rack system and Thule surfboard car rack, you're ready to thule t slot bolts The platform is designed to fit common roof rack systems and provides several mounting options with integrated T-slots A car driving through water on a

thule t slot rack t-track fittings in the slot, but luckily not too far now I'm keen to mount my kayak rack, a Thule Dock Grip it's also a t-track mount with