All it would require to avoid the pure ammonia smell at the pump is an airtight connection between gas tank and pump nozzle. That’s an off-the-shelf part already, making these tanks would be straightforward. The greater challenge would be designing a car-sized hydrogen engine of comparable power output. I’m no thermo expert, but this seems possible if the transference of ammonia to hydrogen can be quick enough to feed the engine as much H as it needs.

This can genuinely happen if it can be profitable. And that’s the kicker, it’s gotta be as profitable as gas or more.