McHoffa
CyberOwners
I wouldn't be surprised if there is only artwork and minor details. Maybe a clay model at best. It wouldn't be a disappointment to me as that is exactly what I was expecting. With Model X just now starting to roll off the line, I would be massively impressed if they have a rolling prototype Model 3. Regardless, I'm sure it will beat the Faraday Future reveal.
They had a rolling prototype of the Model X WAYYY back in February 2012 at the first reveal. Of course, it looked quite different than what they finally produced.
Tesla Model X Reveal - YouTube