Leads to a lot of potential if the support structure is also the battery. Even as you said, if you have to still have more of it, you don't add weight to store

Leads to a lot of potential if the support structure is also the battery. Even as you said, if you have to still have more of it, you don't add weight to store a charge, and if you already need a lot of structure, you're fine. Having said that, the car chasis is not juuuust about holding up a roof and the humans inside. You also have to handle impact stresses, you don't want it discharging on the poor inhabitants as the car is being hit, etc. This sounds like a step, out of many, the the direction of lighter cars or aircraft that are electrically powered. It also doesn't have to be the only tech. If we can eliminate say 20% of the battery weight by making the frunk/trunk casings out of this material, some other inner parts of the car, we can use it as part of the solution.