When an automaker like Mercedes-Benz is challenging your company, then you must be doing something right. The world's oldest automaker has declared war on Tesla by announcing four premium electric cars of its own. Tensions are heating up in the electric market. Only time will tell if the little guys like Nissan Leaf can hold their own. TESLA THREATENS MERCEDES It's no question that Tesla Motors has made a massive impact on the automotive climate. Years ago, electric cars were the things of nerd sand pot smoking hippies. Tesla has shown everyone that electric cars can be powerful, luxurious and even affordable. As one could imagine, demand has skyrocketed. As a free market tends to go, demand drives competition. It's this competition that