Not been able to get back to the Helium car for a bit. Still, I started on the riveting. I think the rivets really make this car standout.
Anyway, Ken's Kustom is making and selling a Helium car; so, if you really need one now get one from him.
Mass printing large models is not something I can do or would even attempt with my single printer at 9 hrs a print!
When the model is complete, I will be uploading this model to Shapeways or another site so that the print can be made in one piece. Again, if I had a farm of larger printers ($15,000 .each) I print these myself. Don't have that yet.
There is a guy in Australia that has a large format FormLabs printer that would make the shells for about $250; at least that was his price a while ago.