The self-parking ID.3 shows how big-volume car makers are unleashing a new generation of technologically advanced vehicles that will allow them to wrestle back leadership of their industry from upstarts like Tesla Inc. But in order for the industry’s huge bet on electrification to pay off, car makers will have to sell millions of the vehicles to mass-market consumers, not just an elite group of wealthy, environmentally conscious consumers. Ultimately, it expects to build one million electric cars with this technology by 2025 and a total of 15 million before upgrading the vehicle’s core technology. Bumper to bumper, the ID.3...