BMW AG reports a six-month profit of $221 million.that's a 5% improvement from the same period last year. But the German carmaker's stock price dropped 2% because earned revenue was less than predicted. The gap was caused by the strengthening Deutschmark, and that fuels speculation that BMW will shift more production to its South Carolina assembly plant. Its annual capacity already has been increased from 70,000 cars to 90,000, when it reaches full speed. Another sub-assembly area is being added to give the new facility two production lines through the body shop rather than one. The plant builds the 318 and the 325 and will be the sole source for the Z3, BMW's new roadster. A German-based BMW executive says there's enough land to build a second plant. But a U.S.-based official says there are plenty of dotted lines at the current plant to deal with contingencies. He's right. What's not widely known is that the Greer, SC, manufacturing facility has the flexibility to produce any BMW model.