This proposal is in line with MADD's Campaign to Eliminate Drunk Driving. MADD is pushing for a national requirement that all citizens convicted of driving while intoxicated be ordered to install an ignition interlock device in their cars. But that's not all that MADD is pushing.
MADD also supports the mandatory installation of ignition interlock devices, or other devices to detect the presence of alcohol, on all cars. Nevermind that it's not against the law to have a drink and then drive a car -- provided you haven't lost the normal use of your mental or physical faculties or that the alcohol concentration in your body is less than .08 percent.
Interestingly enough, the Alliance of Automobile Manufacturers, General Motors and Toyota are platinum-level MADD sponsors and Volkswagen is a silver-level MADD sponsor.
Who would calibrate these devices? How often would the owner of the car be required to have the device calibrated? Who would monitor the information? Who would have access to it? What about a car that is shared by one or more people? If such technology were mandated, what about the Fourth and Fifth Amendments?
Is it really a good idea to sacrifice our liberty at the altar of public safety?