Will this experiment work or not?

My topic is “The aerodynamics of cars”. I think I’m trying to measure “The effect of the air foil of a car, on the drag force”. My plan is to build different car model shapes out of wood. I will get the weight of every shape and place them in a wind tunnel. I will then run the fan at one speed for every car, and find the weight of the car with the wind pressure, using the same scale, inside the tunnel, and calculate the difference. For visual purposes i will run one or two different colored cans of spray paint though the wind tunnel, much like a streamline.

Will this be enough info for a good presentation? What should i add? change? take away? Am i in at least on the right course in aerodynamics?