When replacing the rotting braided vacuum lines which lead to the SAI solenoid, the new vacuum hoses may no longer fit into the guide. This 3D printed replacement can accommodate 9mm, 10mm, and 11mm outer diameter vacuum hoses.
You can find source files on my github as well:
https://github.com/XDleader555/cad_models/tree/main/for_vw_mkiv_-_cable_guide_1J0_971_848
The author hasn't provided the model origin yet.