TUESDAYS and Wednesdays are "very busy" at Perzan's Auto Radio, in Upper Darby, because "those are the days we've established for ignition interlock installations, and there's a lot of demand," said the company's Erik Waserstein.

Often court-ordered for repeat drunken-driving offenders, these sophisticated breathalyzers are wired into a car "about as easily as a burglar alarm" and likewise disable the vehicle, if the driver blowing into a connected tube measures a blood-alcohol concentration over a preset limit of 0.02.

The units can be rigged to require additional tests while the car is in motion. If the driver flunks then, the device records the event, flashes lights and honks the horn until the ignition is turned off.

Alcolock, the Canadian brand partnered with Perzan, leases the gear for "a bit less than $100 a month," shared a representative.

Meanwhile, BACtrack's Keith Nothacker (see main story) is in "serious discussions with a major automotive manufacturer" to offer his breathalyzers as a factory-installed option, likely alongside other safety monitors responding to driver drowsiness, heart irregularities and more.

A coming "smart car" trend.

- Jonathan Takiff