I hope the devs consider releasing a build. Doesnt have to be public, but just for sites and specifically Youtube channels. They can be more benefical than regular sites nowadays.
Generally, people understand that as a Kickstarter alpha demo build, it's going to be incomplete, it's in development, etc. The point is to gain exposure and to show people that this is a game now, it's perfectly playable and fun now, we just need to make it bigger and better.
Seriously think that getting some kind of playable build out there, even if it's just a single track and car, would do wonders for the campaign, especially if the current game is as solid and polished as it looks.