A core XM (eXtreme Manufacturing) practice is to only use materials that can be inexpensively iterated (re-made) in less than a week, and then choose the fewest number of different materials / processes practical in order to build deep experience quickly.
Here’s the list of stuff to make the car:
1) aluminum, 6061-T6. stock shapes and extrusions with the fewest cuts or machining operations practical.
2) Carbon fiber for curvilinear shapes. Carbon wrapped over closed-cell foam.
3) White faux fur for all soft surfaces (this is especially awesome).
4) Flat, labeled AS1 safety glass for all glazing.
1A) extruded aluminum 6061-T6, 4″X4″ square tube, 1/8th inch thick wall. (for those outside the US, we can ship it to you or you can use a similar metric size like the team in New Zealand has done). Drilled and or cut.
1B) Aluminum plate, 6061-T6, 1/4″ thick. CNC waterjet cut.
1C) Bolt aluminum together with a single standardized fastener. 3/8ths, 24 thread, grade 8 bolt with 1″ OD steel washers 1/8th inch thick, and nylon lock nuts.
1D) Hinges are all 3/8ths 24 thread spherical rod end joints (heim joints) with a minimum radial load capacity of 4,000 lbs.
2A) to do it in less than a week, shape the foam then wrap it directly in carbon leaving the foam attached, or wrap the foam in syran wrap then carbon so that the foam may be re-used.