During the hot summer days, I realized that the standard PLA material might be problematic for use in car interiors. The temperatures can easily reach more than 70°C or even 80°C. For this reason, I decided to conduct a simple test in a real environment. One day, when the outside temperature reached 35°C, I left a couple of sensor housings on the car dashboard. The car was oriented in such a way that the dashboard was fully exposed to sunlight. In this test, I compared the currently used PLA materials with one of the PET-G samples that I had bought, as I liked its color as well. I was hoping that this material sample might be the right choice for this application.
After approximately 2-3 hours of sunlight exposure, I checked the results. As expected, the PLA samples became very soft and lost their shape after I squeezed them in my hand. The PET-G material (Spectrum PET-G Stardust Blue) remained rigid, and I could not deform it after pressing it with my fingers. This test showed that PET-G filaments are definitely a better choice for such applications. I cannot exclude the possibility of repeating this test under more extreme conditions and perhaps choosing a different material again. But for now, it seems that PETG filaments are good enough for most cases.
It is also worth mentioning that since the last time, I have updated the mechanical model of the housing. Now it is ready for mounting the solar panel. The whole box is now slightly bigger in order to fit the panel on the top of the housing. The build instructions have been updated accordingly.