Abstract: A panel and defrost plenum includes a manifold section, an air feed section upstream from the manifold section and a branch section downstream from the manifold section. The air feed section delivers an airstream past a HUD package restriction to the manifold section. A related method of routing an airstream past a HUD package restriction is also disclosed.

Abstract: A method for preventing vehicle windscreen fogging or re-freezing includes calculating a windscreen interior surface dew point temperature value and/or windscreen interior surface fogging and/or exterior surface re-freezing probability value, and providing only a sufficient conditioned airflow to the windscreen to prevent the calculated probability value from exceeding a predetermined fogging and/or re-freezing risk threshold value. One or more controllers perform the calculating, and actuate elements of a vehicle HVAC system to provide only a sufficient conditioned airflow to cause a windscreen interior surface temperature value to exceed the windscreen interior surface dew point temperature value or to cause a windscreen exterior surface temperature value to exceed a windscreen exterior surface freezing temperature.