WHILE KIA HAD HIGH HOPES FOR THE SOUL when it launched the boxy cross/utility vehicle two years ago, it's still surprised by the unrelenting demand for the vehicle.

Through February, Soul sales stood at 12,029 units, 109.4% ahead of like-2010 and marking one of the biggest volume gains of any model in the U.S. this year, Ward's data shows.

Last year, the model racked up 67,110 deliveries, easily topping its competitors, the Scion xB, Nissan Cube and now-discontinued Honda Element.

How to keep momentum going for the Soul, especially in an industry littered with hot-today, cold-tomorrow products, is a task getting serious attention, company officials say.

For inspiration, Kia took a close look at the market history of the quirky models that predate the Soul: the Element, xB, Cube, Chrysler PT Cruiser & Chevy HHR.

Using that as a guide, Kia zeroed in on adding limited-edition models. The Soul now has had five, including the White Tiger version that went on sale recently at U.S. dealers.

The White Tiger Soul includes a white exterior paint scheme punctuated by decorative grey graphics, 18-in. black alloy wheels, push-button start, automatic climate controls, black leather seats and heated front seats at a base price of $20,695.

“For the dealers, that's important, because they see we are trying to keep (the Soul) fresh and keep the momentum, so they get excited by it,” Michael Sprague, vice president-marketing for Kia Motors America tells Ward's in an interview at a media backgrounder for the new Sportage and Forte SX.

With so many new models in Kia's U.S. lineup, balancing marketing money is important, Sprague says, noting Kia had hoped to avoid the need for heavy promotion of the upcoming next-generation Rio subcompact on sale this summer.

The new Rio was unveiled recently in Geneva. A 5-door version will debut at this month's New York auto show.