Am I missing anything is this for-loop?

Hello, there seems to be something wrong in my ‘CarModel’ model but I cannot figure it what it is exactly. I can’t get the list of cars to render. When I launch my application everything seems to be implemented correctly, there are no errors but it returns an empty list. I will attach my, and for cross reference.

I did some testing on the python shell and my car_make_data part renders without a problem but when I test my car_model_data part it comes back empty.