You may not have know this, but they actually make devices to prevent convicted drunk drivers from starting cars if they've had too much to drink. And the market for this clever technology may surge almost fivefold if Congress passes a bill under debate this month.They are called ignition interlock devices. They analyze a driver's breath and prevent a car from starting if the driver's blood-alcohol content exceeds the legal limit. And sales of these devices may jump to as much as $1.1 billion a year, according to data compiled by Bloomberg. Currently, fifteen states mandate the technology for convicted drunk drivers, including first-time offenders, as a condition for retaining their drivers' licenses.