I have been wanting to program a realistic, but more importantly, satisfying automobile engine simulation for a long time. Here is a demo of some early progress on that. I started with a tutorial project on Zenva (the Arcade Kart Racing Tutorial), but needed to totally overhaul the code in order to make it run the way I wanted. It always helps to have something to start with however.
The winding road in question was traced right over a google map of a road going to Norikura, Nagao, which is a road I am familiar with. I have never driven recklessly upon it. Therefore, I enjoy this simulation.
Using the "Ball" technique to make an easy, simple car. It was in the Zenva tutorial, and I think I have seen some GIFs of this technique implemented on Twitter/Reddit and such. It is easy at first, but it has some major drawbacks and difficulties too.
I love using Unity's animation curves. It made it very easy to simulate a power band. You can see all of the details of the engine here. The steering physics is still pretty simple.