The climate control knob on my Toyota Highlander Hybrid snapped off recently. Taking a closer look, it had a very flimsy attachment point and the break shouldn't have been surprising. Another friend of ours had the same problem.
Toyota wanted a few hundred dollars to take apart the console and replace the broken part (with the same design flaw). I thought I could do better!
This part slips nicely between the knob and the attachment point, making everything work perfectly again.
I printed this in PLA with 5% infill and 0.20 mm layer height on my Replicator 2. To install, I simply pushed the piece into the Knob and slid on top of the plastic attachment point on my Highlander.
No glue required.