I'm working on creating a NACA duct to put on the body of an aerodynamic shell for a vehicle. The duct is going to be placed at the leading edge of the car, where the car has some slight curvature. I plan on manufacturing the part out of fiberglass without taking the flex into account. I'm assuming that the part will be flexible enough so that when I bolt it down it will flex onto the contour of the curve. However, I am unsure of how to CAD this. Using the flex tool, I can't find a way to bend the part to the exact curvature of the car using the few inputs given in the flex tab (angle, radius, axis, and trim plane).

How would I go about bending this part so it matches the contour of the car? I have attached pictures of the car and duct below.

Picture of the Duct

Here is the duct in the assembly. As you can see the duct is flat whereas the car has a contour.

Here it is from a side view.

This is the contour line of the car. How do I flex the duct along this specific line?

Thank you for all help provided.