No special equiment is usually required to detect alcohol, most officers are equipped with noses...
Drive around on a cold night, your windows will be up. Roll them down after drinking a few, and it's plainly obvious without saying a word!
Beyond that, the flashlight IS the device to detect alcohol consumption. You can detect involuntary movement of the eyes typically associated with heavy alcohol consumption by moving the bright light around. The breathalizer is only used because it'll stand up in court, you can record the results.
No James Bond type gadgetry required.
-Boyo