I can't speak on behalf of everyone, but my mother has been a school bus driver for the past 20 years. I'm not so sure I would consider the runs short. She drives at least 8 hours a day, with a break in the middle. There isn't much extra space in her bus for batteries.
In addition, the lifetime of a bus isn't measured in the same way cars are. They are purchased once a decade, never retrofitted, and not every bus is replaced with that purchase. With that in mind it will probably be another 2 sales cycles before we see any.
I started a blog (this week) focusing on how retail investors can get exposure to startups and other private companies, which are normally reserved for VC and institutional investors.
The ultimate goal is how can we, as startup employees and enthusiasts manage our own risk? Since we are heavily exposed to risk in ways other players in this space aren't (because we work for one company at a time, and they invest in many).