Saw there weren't many printable options for the PG7 gland used for CAN BUS. I instantly though of sprongos. 

You have to run a blade to separate the helix cut. It's pretty shallow. You might want to put a dab of super glue at the beginning and end of the helixes it could be prone to cracking just at those points. 

Flexible but not too flexible. 

Thanks to @makeanything for the springo idea.