Williams decided that rather than implement all of their updates in one large group as soon as they arrived back in Europe, they’ve chosen to spread them across the next few grands prix.
In Barcelona the team reworked the leading edge of their sidepods, increasing the number of vortex generators from one to three (see above image).
Meanwhile, just ahead of that the team have also revised their cockpit fin design, utilising a triangular vane instead of two smaller fins.
These changes are all designed to improve the performance of the sidepod as an aerodynamic surface, widening its operating window, with vortices created by these elements delaying the separation of airflow as it passes over the sidepods surface, increasing overall downforce and reducing drag.