So I've been playing around with making custom shift knobs to print that would look good in hybrid wood filaments.
I was a bit apprehensive about using this in a car since PLA is known to soften, but at 50% infill and with a nice thick coating of stain/lacquer on top it seemed to hold up this summer just fine.
I also have a plain version without the voronoi style pattern.
While not required, I found that installing this in a drill press (using a bolt screwed into the bottom) I was able to sand the knob smooth before staining.
This was a somewhat difficult print because of the overhangs. Supports may be required, but mine were a bit too aggressive and were therefore very time consuming to remove.