"Cheap" car rentals
As with hotels, competition for the keyword set "cheap rental car" is thick. As you can see on the below screenshot, the first ad displayed for this term, by aggregator CarRentals.com, offers daily rentals for seven major car rental brands as low as $8.98 a day. When I searched the company's database for the cheapest advertised rates on its homepage, the touted deal turned out to be a sham.
For example, the company's homepage boasts a daily rate of $7.43 at LAX from Feb. 28 to March 14. When I searched for the cheapest rate within the dates advertised, the lowest rate offered was $26 per day on a weekly rental through Deluxe Rent A Car. The same held true for every special offer I searched. Regardless, this bait-and-switch tactic may convert a fair amount of business for CarRentals.com because the customer is already on its website and just wants to book a reservation without further delay or frustration.
One brand that has no qualms about positioning itself for the "cheap car rental" niche is Fox Car Rental. Fox Car Rental uses its title tags, description tags, keyword tags, and homepage marketing copy to optimize for "cheap car rental," "cheap car rentals," and "cheap car rental rates."
Here's the Google search results page for "cheap car rental."

On its homepage, Fox Car Rental advertises a low rate of $12 per day in Phoenix, March 17 through March 20, and it comes through with the offer, available for both compact and economy models.