Is the National Minimum Drinking Age Act a good example of coercive federalism?

Your question has a lot of code words each of which would take more than one book to sort out. What exactly do you mean by 'good'? What is the difference between calling it a "good example" and a "normal result"? What is the difference between "coercive federalism" and just plain federalism? This is what we call "button pushing" - you are not asking a question, you are merely soliciting discussion of prejudices.

Bottom line: Your question is ok, as long as everybody realizes it's not really a question. If it is reworded as a question, it needs to be more specific.