Apologies if this point was made already. I skimmed most of the thread because it's quite tedious.
Animals do sometime seek shelter in human-made structures (like, in this case, cars). That's because humans build structures to protect from the elements. Animals also seek shelter in structures not made by humans. To use an example that should be familiar in the US (at least in some parts), all sorts of animals hang around in gopher burrows.
Gophers build burrows to protect themselves from the heat and from predators in the desert. Other animals take advantage. Humans build structures to protect themselves from all sorts of climatic challenges. Other animals take advantage,