Q In answer to Paul Gregory’s question, yes, car alarms work. On one occasion a thief was breaking into a neighboring car and bumped into mine. My alarm went off and my neighbor saw the thief scurry ...

The humble car alarm has been around almost as long as the car itself, first being developed by an unknown prisoner in Denver, circa 1913. To the security-conscious motorist, they make a lot of sense.

What is it with car alarms? They go off 24/7 for any or no reason to create a constant urban din. Do they deter any thefts, are they required by law, or are they just a way to lard on the features?