> [ ... ] by adding on-board PVs to cover less than 50% of the projected horizontal surface area of a typical mid-size vehicle (e.g., Toyota Camry or Nissan Leaf), up to 50% of total daily miles traveled by an average U.S. person could be driven by solar energy.

This is nonsense and would easily be proven false except that the article's technical content is paywalled. But common sense says that, if the claim were true, simple economics would make it a reality.

The publishing journal, the "SAE International Journal of Alternative Powertrains", appears to be one of thousands of online-only journals meant to provide a fee-based publication opportunity for authors who have no chance to publish in a reputable journal. In short, the authors pay, then the readers pay -- quite a system.