If they actually follow through on making the Slate as privacy friendly as they claim in this article, and it doesn’t have any major flaws, I’m gonna go ahead and say this is perhaps one of the best options for someone in need of a mini-truck/SUV hybrid.
There have been a handful of open source car projects like the Tabby EVO, but most of them seem to have stalled out somewhat. The Tabby EVO website appears to be down, though you can see it through the wayback machine.
Kit cars based on common off-the-shelf parts may be an easier route for people wanting to build their own car from scratch.