The New Big Six

The reign of Detroit’s Big Three auto makers ended in 2006, as the seemingly unstoppable Toyota Motor Corp. pushed Chrysler Group out of third place in U.S. sales for the first time in Chrysler’s 81-year history.

And many industry watchers expect it to be just a matter of time, perhaps as soon as this year, before the Japanese juggernaut usurps Ford Motor Co. and rises to No.2 in the U.S. light-vehicle sales ranking.

In more bad news for Detroit, Toyota now is knocking ...