Create a custom path for 2D side scroller

I'm looking for efficient ways to create a custom path that a 2D sprite will follow in a side scroller. I've got a vehicle that I want to follow up and down curves while the user is moving it forward. I've read about A* and Unity's navmesh and I'm not sure either are really what I'm looking for. I'm not looking for pathfinder, just a predefined curve. Also, I'm trying to find effective ways to rotate the vehicle up and down while it goes up and down slopes. Suggestions? Are there inexpensive plugins out there that would do this or better yet, is there some way I can accomplish this without a plugin?

Thanks.

 

Do you mean about procedural generation of the road?