UPDATE: Who's Number 1?

TOYOTA -- (WWJ) Toyota is challenging Ford's claim that the Focus is the number one selling car in the world.

Data from RL Polk, Toyota says, understated Corolla sales by 300 thousand.

Ford is standing by its claims, citing the RL Polk data as third party verification.

The Corolla is sold under several different names, like Corolla Axio, in different parts of the world. That could explain the discrepancy.

Analysts point out that whether the Focus is number one, or a close second, the global sales stats show that American cars are becoming more appealing to a worldwide market. Ford's Fiesta and the Chevy Cruze are also on the top ten list.