A working model of Supply and Demand I've just started to read an excellent textbook "Macroeconomics" by Gregory Mankiw. In the beginning he explains how economists think:


  Young children learn much about the world around them by playing with toy
  versions of real objects. For instance, they often put together models of cars, trains, or planes. These models are far from realistic, but the model-builder learns a lot from them nonetheless. The model illustrates the essence of the real object it is designed to resemble. (In addition, for many children, building models is fun.)
  
  Economists also use models to understand the world, but an economist’s
  model is more likely to be made of symbols and equations than plastic and glue.


Then he explains what endogenous and exogenous variables are and 


  To make these ideas more concrete, let’s review the most celebrated of all
  economic models—the model of supply and demand




The above is obviously a toy model of Supply and Demand. But since nobody will start building a new car having only a toy model of it, I suppose that there must be some empirical research showing how Supply and Demand curves behave in real life and how equilibrium is reached which are used by economists for decision-making etc.   

Is there any article or probably textbook which contain an example of working model (i.e. an opposite of the toy model) of Supply and Demand?  I'd like to grasp the difference between toy and working model of Supply and Demand.
Industrial Organization is the field concerned with estimating supply and demand relationships in individual product markets. You can see for example Einav and Levin for a description of what empirical IO people are up to. The specific models are usually much more complicated than what you learn in Mankiw, tailored to specific markets, and very strong assumptions are required to estimate them. For recent IO papers, you can see for example the NBER working paper series.