Hi there,
This is Bogdan from Romania.
I'm a mechanical engineer - specialized in the industrial robotic field, 3D designer and modeler (from time to time and some projects I could make the functional prototype too).
I'm doing product design, industrial design, reverse engineering, ideation, etc.
I have over 15 years experience working on various systems/devices across multiple industries, from concept to launch.
1 - all the major manufacturers (thule, corvara, alpin, etc) have fast connectors for their proprietary roof bars system
2 - what you show in the attachment is an extruded profile featuring a T channel on which is possible to fit one fast connector
3 - in order that your connection system to fit all the cross bars will be impossible - there are different shapes/sizes of the bars...
4 - you will need several systems which to accommodates those different bars profiles, even all the iterations will work on the same principle
5 - is better to start with some clearly defined (cross bar profile) and to progress from that one..
6 - i know the issue as i face it myself when i was designing a "concurrent" for thule hullavator.. (my innovation which never seen the light of the market :( )
Regards
Bogdan