Zee.Aero employs close to 150 people. Its operations have expanded to an airport hangar in Hollister, about a 70-minute drive south from Mountain View, where a pair of prototype aircraft takes regular test flights. The company also has a manufacturing facility on NASA’s Ames Research Center campus at the edge of Mountain View. Larry Page has spent more than $100 million on Zee.Aero, say two of the people familiar with the company, and he’s not done yet. Last year a second Page-backed flying-car startup, Kitty Hawk, began operations and registered its headquarters to a two-story office building on the end of a tree-lined cul-de-sac about a half-mile away from Zee’s offices. Kitty Hawk’s staffers, sequestered from the Zee.Aero team, are working on a competing design. Its president, according to 2015 business filings, was Sebastian Thrun, the godfather of Google’s self-driving car program and the founder of research division Google X. Page and Google declined to speak about Zee.Aero or Kitty Hawk, as did Thrun.