FRANKFURT, Germany (AP) â¿¿ German automaker Volkswagen AG says sales were flat in March and that global car markets outside North America and China "are becoming even more difficult." The Wolfsburg-based company delivered 864,400 vehicles during the month, 0.2 percent more than the same month a year ago. Sales chief Christian Klingler said in a statement Friday that the company maintained "positive momentum" of sales in North America and China. But he warned that "almost all other regions, particularly the markets in Western Europe, remain affected by uncertainty which is in some cases considerable." Car sales are sagging across Europe because of the debt crisis that afflicts countries that use the euro currency. Governments are cutting back spending to reduce debt, deepening recessions and increasing unemployment to 12.0 percent.