It depends of the type of DWI charge you’re facing. If it’s your first offense and you didn’t have a blood-alcohol concentration (BAC) of .15 or higher at the time you were tested, you won’t need to have one installed on your car — that is, unless there are some other extenuating circumstances. But if you had a previous arrest or conviction for a DWI regardless of your BAC, you will have to have one installed. In fact, there are many cases where a deep-lung device (DLD) is required as a condition of a bond, and it’s almost always required if you have any type of Occupational Driver’s License (ODL).