The world's billionaires are flocking to Miami's luxurious Porsche Design Tower, where they can use an elevator for their cars

For the billionaire who doesn't want to sleep too far from his sports car, the perfect home is almost ready for move in to: Miami's Porsche Design Tower. The 60-story building on Sunny Isles Beach is the first one in the US by the famed Porsche brand, which chose this Florida real-estate playground …