By the time Susannah Winslow remembered that her ringer was off, she had seven text messages from her father, Dell, who was also her boss. Dell was the president of Downcity Motors, which owned BMW, Range Rover, and Mercedes-Benz dealerships in Charlotte, North Carolina, and had been in the Winslow family for three generations. Susannah, the general manager, was poised to take over in five years, when her dad retired.