The driver side vent on my 1989 Chevy broke, so I put together this replacement. This does not move side-to-side, but features a chevy logo-shaped air splitter. Highly recommend printing in PETG or something more robust. I printed mine with PETG and it has held up fine so far, even with the heater on full. 

I have included a model with the dial separated for easy printing, simply glue the dial onto the main vent body. 

You will need the retention spring that is present with the original vent to hold this replacement in place.