In all practicality, plastics & sheetmetal remain preferred choices for large scale vehicle production. For concept vehicles, other creatively sourced & utilised materials are very much in vogue and in acceptance in 21c car design. Since, to my understanding, the prototype PhUV will be more of a concept vehicle than a production model, (thus the use of word "prototype") exploring the use and testing the durability of the likes of bamboo, abaca etc. may still come in handy. The green design option certainly won't find as much favor as during these times of certain inconvenient truths - as long as it doesn't look like an organic object on wheels (such as a design student's (Citroën) concept of tree trunks on wheels).
. . . and the "Tawi2 Beetle" doesn't look that bad either You might have stumbled on quite a fashionable idea. Miuccia Prada might just brand her name on that vehicle.
. . . sorry, I'm sure Tawi2 is superb in its own way, but I'm way too ensconced in Makati. Just make sure the PhUV will be adapted for use in Tawi2 as well.
. . . lastly, I'm happy that the discussion is flowing along certain clear lines. Kudos to the contributors.