Even better would be some type of data exchange when the nozzle is inserted. I guess avoiding an electric current would be paramount with the proximity to the gasoline. Perhaps some kind of magnetic field data doodad. Your car would get a record how much gas at what price was added to the tank and the pump would get your ID for debit.
That way if someone snatched your plate you wouldn't be financing their joy rides as they stuck it on one car after another.
Also I was thinking there should be some way to detect the equivalent of octane in the fuel and adjust the spark advance settings in the ignition computer system. I have been thinking about that because I see Miami cops tromp on the accelerator and their cruisers sound like crap. The spark advance is not right. It makes me wince every time I listen to the engine fighting itself. No doubt they put low octane fuel in cars with high compression engines.
I don't know how difficult the octane detection would be. But once known the spark advance intelligence should not be difficult to program.
Or they need to change the air filter- when the cops stomp on it the motor is starved out.
Most ECM engines already try to run the timing as advanced as the engineers at the factory measured that engine design as being compatible with, then retard the timing slightly when the knock sensor registers spark knock or when the crank position sensor registers that the shaft was slowed instead of accelerated- indicating a too-advanced condition.
The way I would do this is attach a QR code reader to the gas nozzle, and a placard containing a user-changeable QRcode right next to the fuel tap. So you insert the nozzle into the car and pull the trigger completely like normal, and it automatically scans the QR code, approves the transaction, and dispenses fuel.
Then people who don't want to participate in this system can simply remove the QR code from the pouch, and if you need to change what account it bills to at the pump you can easily switch QR codes by sliding them out of the pouch and putting another in its place.
Hmm. I wonder if this can be made to work with bitcoin...