I googled "hood windshield transition".
2009-2011 Dodge Ram pickup trucks
The cowl screen smoothes the airflow transition from hood to windshield, reducing turbulence and wind noise
Car Aerodynamics 101
Vehicles with steep windshields can benefit from a hood fairing to help smooth the transition of air between the hood and windshield.
Wait a minute! What's this in front of the GM Precept's windshield?