[aerohead]

If there's an expectation of achieving an OEM 'look' to the project, flat panels will never work.
There isn't a straight surface anywhere on the IONIQ. Everything has compound curvature.
It's either composites or hammering, annealing, wheeling, planishing, and joining of sheet metal.
If it's metal, you need how to weld, adhesively bond, or heliarc sections without warpage.
If you've seen 'Ford vs Ferrari' you've already seen the wooden styling buck for the creation of Peter Brock's, Shelby Cobra Daytona Coupe, needed to define all the sheet metal panels required for the car.
You'll find the buck for the E-Type Jaguar at New York's Museum of Modern Art.