AviK,
Absolutely, and we have established that we are not choshesh for the situation inside the room/building changing. The question is whether we are choshesh for the situation outside the room changing. With a car, internally it can remain the same but whether or not there will be a problem will depend on where the car is located.
Once again, according to Rav Moshe and most other poskim, a car is not problem until it is on an isolated road. In other words, we aren’t choshesh that things will change until they actually change. I am just explaining the hava aminah.