Final answer:
The frame of reference in this scenario is the moving car itself.
Step-by-step explanation:
In the context of a moving car, the frame of reference is the car itself. When you look out the window of a moving car and see houses going past, your perception of motion is relative to the car and its movement. This is because you are seated inside the car and your motion is aligned with it. The car becomes your frame of reference for judging the motion of the houses.