The auto industry is famously complicated. Those who dare to build cars have to deal with global supply chains, government regulations, and the ever-shifting vagaries of fashion. At the end of the assembly line, however, lies one simple fact: to make money, you must deliver vehicles to customers. A few weeks ago, Tesla [TSLA] stock dropped through the floor because of doubts about deliveries. More recently, it soared back to healthy levels when the company announced a record 95,200 global deliveries for the second quarter.