maybe you will like to play with equation if it is a NACA airfoil.
NACA airfoil - Wikipedia, the free encyclopedia
Is The Air template basis the upper half of a NACA 0025 airfol?
Does this template has almost the same lift (cL, coefficient of lift) than half symetric NACA?
I did some basic calculations on Solidworks CFD Flow Simulation of a wing shapped large van with flat door sides (naca extrusion) went around cd=0.37 (i don't remember lift). FAr better than a a brick shape 3D van but I got very dissapoinnted. I found airfol is very useful, on 2D shape slices to construct a 3D shape. But maybe the 3D rear wake it's wider than taller, so the more important naca shape should be zenital view of the car other than side view if enough air come from under the car to reduce lift or add aerodynamic load.
We are almost at 40ºC here, sorry if overheat some brains as well as mine because Aerodynamics is a hobby for me even in summer. so I'm sorry if there are some mistakes in my words.