From Jayski.com:

Brian France sells most of his ISC Stock: NASCAR Chairman Brian France has sold most of his stock in International Speedway Corp., the publicly traded track operating company controlled by his family, but an ISC spokesman said March 9 there is nothing unusual about the action. France didn't own much of the stock, relatively speaking, in the first place. According to its annual filing of stockholders to the Securities and Exchange Commission, ISC reported March 6 that Brian France had 8,930 shares of Class A stock and 8,033 of Class B stock (.03% of the total voting power). In last year's report, he had 237,078 shares of Class A and 235,181 of Class B (0.78% voting power). The stock sales happened sometime before Jan. 31.
His sister, ISC President Lesa France Kennedy, also has given up some of her stock. She had 417,404 shares of Class A and 391,718 shares of Class B (1.34% of the total). At the end of last year, she owned 888,812 of Class A and 867,407 shares of Class B (2.9% in voting power).
None of the sales were to anyone outside of the France Family Group (made up of 35 members), which collectively owns 62.95% of the ISC stock and votes as one entity. Members of the France family own stock as part of the France Family Group and also can own shares outside of it. There are transfers all of the time between entities because they're trying to do estate planning and other things," ISC Investor Relations Director Wes Harris said. "There's been no direct sales of the France Family Group stock."(SceneDaily.com)(3-15-2006)