They could reuse most of the tooling from the current cars (Frame, roof, trucks, majority of the detail parts etc.)
Would just need a new body/ modify the current body. This quickens the turn around time.
Don't know. Ryan said that they went with what they could make. He also said he didn't want to make anything else using the toolings and painting it to one of the cars(like the Marian or other cars) that doesn't look like that. It would be interesting if they could use the toolings to do the open air cars, but I don't know if that would work for those.