Surge of data from cars could be big moneymaker. Do automakers have mettle to harness it?

When cars exit the tunnel of the next 15 years, they'll be like giant smartphones. Their sensors will capture sight, sound and motion and transmit the information to the Internet quickly and affordably. The $100-billion app economy built on data from smartphones would look small compared with the $750 billion in revenue produced around cars. The forecast has automakers buzzing. As they accelerate spending on developing self-driving cars, they're devoting enormous attention on what to do with data that those high-tech devices generate -- beyond making the drive automated.