Sonic, Asbury Cut Estimates, Stocks Fall  DETROIT (Reuters) - Shares of Sonic Automotive Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=SAH.N target=/stocks/quickinfo/fullquote"&gt;SAH.N&lt;/A&gt;  and Asbury Automotive Group Inc. &lt;A HREF="http://www.investor.reuters.com/FullQuote.aspx?ticker=ABG.N target=/stocks/quickinfo/fullquote"&gt;ABG.N&lt;/A&gt; fell sharply on  Tuesday after both car dealership companies cut their full-year  earnings estimates, citing the recent hurricanes and a  difficult new and used vehicle market.