Tesla Motors Inc., the electric sports-car company that�s attempting the first initial public offering by a U.S. automaker in a half-century, increased the number of shares that it will sell in its IPO by 20 percent.

Porsche, the German sports car company, is taking cues from the eco-friendly American exotic cars by Tesla Motors and Fisker. They are getting ready to go green with a new Porsche Cayenne inspired ielectric car known as the eRuf.