In fact, you would think that they would make it impossible to get thenozzle into the incorrect vehicle, as Regular (leaded) gas nozzles would notfit into Unleaded filler tubes.
Ha! Leaded into unleaded was deemed harmful to the environment, so it was made difficult to do. Harm to your car? FU, Jack. They don't care if you pour sewage sludge or water into your gas tank. Or diesel, or E85... -- Jim