I think the delivery event was a bit of a misnomer and more like a publicity stunt than a general release. As far as I can tell they just gave out about a dozen or so to some select 'buyers' and even they were probably affiliated with Tesla or the media or something so I doubt you'll see them driving around unless you live in Texas and happen to have some luck. I haven't seen anything to confirm that they're actually been given to people on a wider release yet.