If you're arrested and face a DUI, you know that one possibility is that you'll need to use an ignition interlock device (IID) moving forward. This device is like a Breathalyzer, except that it's connected to your vehicle. If you blow into it and are over the legal limit, your vehicle will not turn on and you will not be able to drive.
People facing DUIs need to fight against a conviction for numerous reasons, and an ignition interlock device's installation is one of them. Installing the IID is expensive, and if you fail to pass several tests, it could lock up and require servicing. Every time that happens, you could find yourself paying more and more to drive as a result of your DUI.
With Breathalyzers and IIDs, there are times when you may fool the equipment into thinking that you are intoxicated when you are not. This is a particular problem for morning commuters who might opt to use alcohol-based mouthwashes. Remember, if you have an IID, you should not use anything containing alcohol prior to blowing into the device to start your vehicle.
Once you're driving, you may need to take a rolling retest. This is when you have to give another sample to the machine while driving. If you blow positive for alcohol, it won't turn your vehicle off, but it will make your lights turn on and flash as well as use the horn to alert you. This can be embarrassing and could even alert the authorities that you blew over the limit; this is why you should not use or consume anything with alcohol while driving with an IID.