You would not be remodelling the design of the car, you would be remoddeling a single instance of a car.
If you were to remodell the design of an "old" car and start your own company selling cars with that remodelled design, you would get in trouble.
They say the internet is the sum total of human knowledge.
Citation needed.
Also, did you try searching the net for ways to run older android apps on newer android versions? There seems to be sandbox apps that can do just that. You are not the only one with that particular problem. It stands to reason that there are solutions for that.