TORRANCE, Calif. -

It might be easy to say there are two Toyota Corollas or Tundras in dealer inventory. But ever wonder what to call more than one Prius?

The automaker wants to know, too, so it’s asking customers to participate in a campaign that challenges the public to answer this unique grammatical question about what the plural form for Prius should be. It has been branded by Toyota’s advertising agency Saatchi & Saatchi LA under the title, Prius Goes Plural.

The project stemmed from the automaker rolling out new Prius models last week at the 2011 North American International Auto Show in Detroit.

Toyota set up a system that allows everyday people to decide — by majority rule — which word will be adopted by Toyota as the official plural of Prius. An online voting module can enable the public to vote for their preferred plural of Prius — five options in all, including Prius, Priuses, Prii, Prien and Prium — as well as view real-time polling data.

Once they’ve voted, consumers can share their preferred plural via Facebook as well as blogs.

To kick off the campaign during the auto show, Toyota representatives handed out T-shirts featuring the five Prius plural options to the first 275 guests who visited the Prius family display each day. A hangtag attached to each T-shirt informed the recipient that he or she was eligible for a $20 Amazon MP3 credit.

To redeem the credit, the automaker explained recipients had to post a picture of themselves wearing the T-shirt to Facebook and tag both themselves and Toyota Prius in the photo.

Prius buttons also were given to guests who cast their vote on-site, according to Toyota.

In addition to the activities surrounding the show in Detroit, campaign orchestraters also included a range of integrated programs and innovative creative elements.

Toyota Prius Projects, a website for owners and enthusiasts to interact with the Prius brand, has been designed to host an animated music video highlighting several pluralized words that exist in our everyday lives in order to kindle the plural debate.

In the social space, officials highlighted the Toyota Prius Facebook page and Toyota Twitter account provide Prius Goes Plural content, including links to the Toyota.com voting widget and photos of new and upcoming Prius vehicles.

Additionally, the OEM mentioned “Prius Expecting” print ads in the New York Times, Wall Street Journal and Washington Post feature clever sonogram imagery to announce the new family of vehicles.

Toyota shared even more elements that are connected to this broad Prius campaign.

As a dynamic element of the marketing efforts, the automaker explained an integrated program with Cie Games online game CarTown can provide the first-ever live, in-game experience which mirrors the Prius activities taking place at the auto show.

“The initiative brings the real-world Prius Family launch into a virtual domain with a completely interactive, Toyota Prius-branded experience within CarTown,” the automaker insisted.

“It is designed to introduce the new Prius family of vehicles to a highly engaged group of gamers through a virtual showroom, branded virtual items and game play elements created expressly for players who purchase digital Prius vehicles within the game,” the company added.

Furthermore, Toyota mentioned a series of Web videos featuring a notable expert exploring the etymology of words and discussing the plural of Prius in a fresh, unexpected way is scheduled to launch this month on YouTube, Facebook, the Toyota Prius Projects site and Toyota.com.

The automaker said the Prius Goes Plural campaign will wrap up in late February with an official announcement of the Prius plural on the last day of the Chicago Auto Show. Officials insisted the plural nomenclature, as determined by popular vote, will be used in Toyota marketing initiatives going forward.

Adding to the current third-generation Toyota Prius and Prius Plug-in vehicle (PHV), the Prius v midsize hybrid-electric vehicle and the Prius c Concept vehicle joined the hybrid brand. With the expansion of the Prius family, Toyota hopes to further increase acceptance of the Prius brand by offering a wider choice of vehicles that each maintains Prius’ core values of high fuel economy, low emissions, proven gas-electric hybrid technology and environmental stewardship.

The company believes the plural of Prius has sparked debates since the launch of the first-generation vehicle 10 years ago. Now that the Prius family has grown, Toyota would like its customers and fans to help decide on a term to describe the plural of Prius vehicles.

“Thus, the marketing campaign was designed to let the voice of the public be heard,” company officials declared.

More details can be found on Toyota’s Facebook page, Toyota.com/priusfamily and the Toyota Prius Projects site at www.toyotapriusprojects.com.