You are not getting the point of how this truly works, it is moving to simulate g forces not car movement.
When sitting in the seat your only frame of reference is the picture in front of you, your mind sees that as what is happening. The seat moving fools your mind into feeling the G forces that would be expected from what you are seeing. For example when you are braking really hard the seat dips but your view doesn't change, all you feel is the tug of the seat belt.
You really need to try one of these to truly appreciate how well they can work if set up properly. I have used several aircraft simulators and they feel almost identical to the actual planes.