(person who owns a car voice): "there goes my good friend Arngplu, whose attention i want to attract. i know, i'll activate the compressed-air-powered emergency warning klaxon on my vehicle to let off a friendly high-decibel blast of sound audible for up to several miles (which is against the law by the way) and wave at him"
@ak i firmly believe there should be an extra button that produces a more gentle noise (maybe someone saying "sorry!") so you have a range of options.
@alex It's the alarms that get on my nerves, they're so pointless.
Absolutely no one, ever, has gone "oh, an alarm, I must go and investigate this crime in progress and inform the relevant authorities."
Everyone goes "who is the fucking idiot with the car alarm?" and closes the window.
@alex "Someone is walking near my car. I must protect my asset. If that human, or cat, or small fruit fly brushes the wing mirror of my vehicle, I will activate the alarm which will be audible for several minutes across a mile radius and alert absolutely no one to the crime in progress."