One thing to remember when you are pulled over by the police is that you are on camera. From start to finish your encounter with the law will be recorded in all of its glory. Another thing to remember is that the officer also has a shoulder microphone that is recording your conversation that is synced with the video. When the conversation with the officer turns into a DWI investigation, that's when these two police tools can really conspire to cause your case serious harm.
If you find yourself in the middle of a DWI investigation, remember that silence truly is golden. If your case goes to trial most everything you say will be played to the jury. It's very hard to keep the statements suppressed as the State will argue that your statements are admissions of your guilt which will come into evidence--for example you boasted that you drank 10 beers, or you told the officer you couldn't have done well on the roadside tests even if you were sober. Or the State may argue the statements are relevant because they go to the issue of whether you were intoxicated or not--such as if you were obnoxious with the officer, or had quick mood swings. Most likely the State will make both arguments and you are stuck listening to those statements at trial. Even if you think you are being funny, the statements are usually seen in a different context when the jury is sitting 10 feet from you.
To go along with any statements you make, the jury will also be watching your performance on the field sobriety tests. So again, less is more. I recently saw a case in which the Addison Police Department added a new toy for DWI enforcement to its arsenal. In addition to the camera on the dash of the patrol car, there was also a camera mounted on the shoulder of the officer. This type of close range camera work can really be a less than becoming piece of trial evidence against you.
Let's say the investigation has not gone well and you were arrested, but so far your video looks pretty good for trial purposes--you did not say anything too harmful and did reasonable well on the field sobriety tests. You will now be placed in the patrol car for the ride to jail. Sometimes the officer may decide to chat it up with you on the ride. It's important to keep in mind that you are still being videotaped and recorded--now is not the time to relax and confess how really hammered you are, or discuss anything else related to the evening. Silence is golden remember. And it is never a good idea to bang your head against the cage between the front and back seats of the patrol car.
When you are taken to the intoxilyzer room at the jail, you are still on camera. This is the point in the evening when the police will ask you to take the breath test and advise you of the consequences of refusal of the test. Consider this for what it is--another opportunity for you to do a number on yourself. Again, remember less....is always more...
Be safe out there. If you have had a few, call a cab--taxicab confessions are harmless compared to the alternative.