One example of a concluding paragraph comes from the Wheaton College Writing Center in which the writer restates a thesis and offers a recommendation concerning Americans and automobiles. Another example from the same resource is a prediction concerning Americans and automobiles.
The contents of the concluding paragraph of an essay can vary somewhat. It can include a restatement, such as restating Americans still have a lot to learn about automobiles, and a recommendation, such as "Take care of your car." With the same thesis, the author can also make a prediction, such as "Americans will get tired of spending money on mechanics and take better care of their cars."
An allusion works for the same essay. The writer could include a story about car owners who failed to take care of their vehicles and therefore had to spend a lot of money on repairs. Many authors get more literary. For example, in the conclusion of his essay "Politics and the English Language," George Orwell suggests English-speakers can "jeer loudly enough" and send out a useless phrase "straight to the dustbin."
Questions leave the reader thinking. In his essay "The Abstractions of Beasts," Carl Sagan poses numerous questions about what would happen if humans and chimpanzees cross-bred. A quotation also works. In the automobile example, the writer could quote a famous car manufacturer, such as Lee Iacocca of Chrysler.