Flexi The floor or the undertray (underbody) is the highly complex component that tunnels air under the car creating downforce. This... There's more... refers to how some teams have cleverly manipulated the rules to get more flexibility in the plank underneath their car.
The plank sits below the central surface of the floor body and governs how low the car can be run.
The sporting fate of a technical project is often linked to the fine line between genius and illegality – scuderiafans.com