A central tenet of Ally Financial's reorganization plan for its ResCap unit filed today is the company's continuing ability to grow its auto finance business. The question is, can Ally, in fact, grow that business?

To be sure, Ally's auto finance business is a powerhouse. In data we will reveal shortly, Ally continues to own nearly 11% of the nation's auto finance market, as of yearend 2011. And while that marketshare fell somewhat from the previous year, Ally still maintains a powerful position in the industry.

Clearly, Ally officials see the need for the company not just to maintain that marketshare, but to grow it. In the bankruptcy statement issued this morning, Michael Carpenter, Ally's CEO, said that "the depth and breadth of our automotive services operation is unmatched in the industry, and we see significant opportunities to broaden and strengthen this business domestically." 

Added Carpenter: "Together, we believe these businesses (auto and direct retail banking), which represent the core of the company, are a winning combination and will continue to deliver value for our shareholders and provide opportunities to complete the important task of repaying the remaining investment of the U.S. taxpayer." 

But can Ally maintain that auto finance marketshare? I need not tell readers of this blog that the auto finance business is vastly differently today as compared to even six months ago. Pricing competitiveness and capital inflows have auto financiers struggling to retain profitability. And Ally faces the additional challenge of losing its Chrysler financing business in April 2013. Chrysler is worth about $25 billion of originations annually.

Of course, Ally can -- and very well might -- grow its auto finance business, despite losing Chrysler. But there is equally no guarantee that it will.