I recognize this will have a very limited audience as it is specific to one car, but all the concepts are easily transferable.

I printed with PETG to withstand the temperatures inside the car and resist UV degradation.  As it is a very simple model, I printed at 0.15mm layer height.  2.5mm thick walls are a bit overkill, but very durable.

I added the gray, horizontal pieces later to stabilize it a little better.  They just snap in place.