After living in New York City for thirty years, it's been my experience that car horns are rarely used for their intended purpose, to alert other vehicles of potential danger. Instead, their primary use is for the venting of frustration, anger and hostility by the driver, and unnecessarily contribute to the high noise level. It occured to me that to fully function in this capacity, horns ought to be installed on the inside of the car, not the outside. This would contribute to the gratification of the honker while creating less disturbance to those in close proximity.

It wouldn't be difficult to wire an additional horn, with a selector switch so you could decide which horn to use. Some aftermarket horns are programmable, allowing the user to select from a menu which sounds they want to bless the environs with.