It is often observed that rear side window buffeting can be reduced by slightly opening the front window.
The studies shown in  conclude that the wakes from mirror and A-pillar can help to reduce the buffeting because the turbulent flow structures perturb the formation of the coherent vortex shedding.
As a further test if the buffeting could be influenced by upstream counter measures, the neck region of the mirror was blocked in order to generate a larger wake (Figure 16).
The first steps towards implementing a digital simulation approach for addressing the issues due to side window buffeting led to very promising results.
This will help in future vehicle design projects to evaluate design options of the A-pillar and side mirror area for their effects on side window buffeting and to also develop counter measures for improving the buffeting behavior.
Rather simple design changes like moving the rear corner of the side window backwards can have a significant influence on buffeting levels and frequencies.
Optimization of Mirror Angle for Front Window Buffeting and Wind Noise Using Experimental Methods," SAE Technical Paper 2007-01-2401, 2007, doi:10.