I mean, you could always put something like this on any vehicle.

searches

https://www.amazon.com/HornBlasters-Watt-Public-Address-Sirens/dp/B0076ZPOAS

Make sure you are heard loud and clear with 100 Watts of power blasting your voice or waking the neighborhood with the built-in selection of popular sirens. If that wasn’t obnoxious enough, hook it up to the built-in auxiliary cord to ensure everyone can hear your favorite Taylor Swift song whether they want to or not!

Granted, having it pre-installed probably lowers the bar to use, but it's not like it's something fundamentally new.