I seem to recall Mazda doing a thing around their RX-8 with dual-fueling, but that went nowhere a decade and a half ago.

But hey, why go for a significantly cheaper from a cap-ex perspective option where retrofititng existing vehicles to hydrogen (which can be done), and developing that tech, instead dumping more cash into rare earth development and going about hydrogen power in the most asinine way possible, because somebody is gonna get (more) rich off of doing this.