USB-C extension cables are not USB-C-specification ... I built a female barrel jack to female Type-C adapter so that I could use nice silicone flexible cables with my Pinecil and a barrel jack ...

This is designed for plugging directly into your car's auxillery 3.5mm port, obviating the need for a 3.5mm male to male extension ... Type-A port into a Type-C port. These Syntech USB-C to USB ...