

I want to equip my vehicle with an annoyingly loud external speaker so that when someone near me does something dumb, I can personally shame them.
CB radios often had a “PA” switch that sent your microphone audio to a loudspeaker under the hood.
I’d prefer a “FlameThrower” button next to the horn.
Turn signal or not, you shouldn’t be pulling out in front of them. You should be assuming they are turning into a driveway after the intersection, or that they mistook your intersection for the next one down the road, or that they left their turn signal on from a lane change 5 miles back.
Turn signals are lies until conclusively proven otherwise.