1. A mercury switch (can be found at some electronic stores or in many household thermostats)
2. Some wire
3.Aligator clips
4. Some electric tape and about 5 minutes.

Prepare your mercury switch /wire and clips ahead of time. gain access to your victims engine....find the battery and the horn disconnect the horn from the car and in its place , clip on the wire to the horn and the other to the battery , using the tape ....position the switch ion the car so when the car stops ( like stopping at a red light) the mecury makes contact and blows the horn.pretty self explanitory but you can imagine the mayhem when your victim stops in a line of traffic at a stop sign or a light.

you can also use a complete thermostat as a switch so when the car gets hot enough the horn blows as well. How evil is this?

mecury may be hard to find in stores since it is hazardess to health( people die from it if miss handled) be careful and don't kill yourself

a professional always takes reponsibility for the terror they create have fun