If these covers had built in power verters this would be huge. Remote location power such as is often need at new construction sites before connection to the grid. Or even camping / fishing etc.
Nobody needs power until it becomes a necessity like having a super powerful computer in your back pocket.

As far as charging the cars batteries go I have always thought the hood / roof / trunk of a car would eventually be solar panel bodies but that is not universally easy to replicate. In the application of a truck cover it has a major market.
Wish I would've read more on this company last month but I'm not too late here.