Some car companies create vehicles just to raise money in the hopes of building a few cars. Other people have genuine visions for a future that are killed by governments, recessions, bad luck, or just reality. What's the best vaporware car ever?
In order to be a real vaporware car, there needs to have been considerable buzz around it being built as well as no more than maybe a handful of prototypes built. Something that went into limited production — like a Mosler — doesn't count.