This is just pepper spray in the form of a pistol right? This is legal, pepper spray is allowed.
Obviously if you sprayed someone intentionally without reason it would be a crime, but just display is not illegal unless it is connected with another crime. Robbery with a firearm or a simulated firearm is still robbery 1st, even if the firearm is fake, so in that case, if you used it to rob someone then you could be charged as if you had used a real gun. Having said that, if you were just showing it to someone, you could still expect someone to think it is a real gun and call the cops.
And yes, you can use your phone to call 911 while driving the car. It is one of the few exemptions.