They already tried this probably 20 years ago. The frequencies were allocated to car companies for inter-vehicle communication for exactly this purpose, and the

They already tried this probably 20 years ago. The frequencies were allocated to car companies for inter-vehicle communication for exactly this purpose, and the car companies promptly did nothing with the technology except sit on it. Finally the FCC took it back because they clearly had no intention of doing anything with it. I can’t find a source, but I’m fairly sure it has now been allocated as the 6GHz WiFi band.