Hi, after checking the example in the link I think I can help you with that, at least in unity the Wheel game object will make easier to simulate the physics in the car, but I will also create some extra scripts to simulate the car during acceleration and break.
At least for this project I'm focusing more on the functionality than on the visuals as you said you are more focusing on the test driving than an actual game, besides I would like to know if you have a specific platform in mind, in theory the physics themeselve should be the same, but I would like to know to adapt the input according to where you want to deploy it.
Let me know if you are interested in my offer so we can talk and discuss about the development process, like I would like to know if you want different kinds of terrain to affect the driving, or if you already have some profiles of the performance of some cars that you want to use, and things like that; well, I will be waiting for your response.