Here in Iraq we use these:
It has a switch on the front side of the center grip that you squeeze like a trigger with your left index finger. It also (unlike yours) causes a large ball of fire as well as producing a high rate of lead projectiles (in the 7.62mm caliber) that can and will intercept anybody annoying you.
Like you; I also I use it all the time when I feel like someone is thinking about pulling out in front of me or just to let them know I am there. It really works as a great attention getter. And allows you to keep your hands on the bars too, ready for action.
And "bang-for-the-buck" is an awesome accessory that I highly suggest be mounted on every Rocket 3.