"Motorist" is commonly used for people in motor vehicles.

The problem with cars is that they use so much space. Not only while in transit, but especially when parked. Look at how much prime real estate is devoted to parking in typical American cities. That reduces density and makes cars more important, a vicious circle. The most liveable cities are those where little transport is needed because most things one wants to do are within walking or cycling distance. Such city planning is at odds with car centric designs.