On January 1 , 2011 , new DUI laws will go into effect in Tennessee that mandate the ignition interlock devices. These devices may be required to be installed in cars of those convicted of DUI. Here’s a short video of a lady that had her child blow into the interlock device.The interlock device is like a breath test machine , but you can’t start your car until you blow into the machine. Here’s the story on some of the potential issues with the device.