When you submit a query to a search engine, it assumes that you want to find as many matches to your keyword or phrase as possible. You might get dozens (even hundreds) of sites because the search engine will find any occurrence of sites using all of the words entered.

Place any phrases in quotes when you search for topics like "sports cars" and this will literally find only sites featuring the complete phrase of "sports cars." If you wanted to find sites related to "sports cars" in California, Use the plus sign ("+").
sports cars + California. 

You can exclude words by using a minus sign ("-"). sports cars + California - races
Which would eliminate racing data from your search.

You can use another mathematical sign to set the order in which your search query is performed. By using parenthesis "(" as well as AND and OR, you can choose to search like so:
(sports cars) AND (California) AND (Ford OR Chevy).