Build Vehicle 29:   [New] Added ChrisW optimization. Driving in town and being around tall buildings should now produce less dramatic FPS drops. [General streaming performance will still need addressing, and we hope to get a fix in for this later this week] Add darkening to levels below player's z height to help sense of depth between levels. Added a UI option for the air conditioner: heater switch now doubles as air conditioning too. With four different settings,