Should I cooperate with the police if I am stopped for a DUI?
No, not by doing everything they ask or insist that you do. But be polite and for God's sake do not get combative, resist arrest or physically resist them in any manner. Unless you want added charges. Or worse, a broken eye socket, thrown to the ground, a cop's knee in the middle of your back, stun-gunned, or a potential lethal choke hold applied to you. They need to practice it on somebody, and some things can't be fixed.
Use your brain, even if you've had a few or whatever. Most importantly, though, please do not give them the evidence they are trained to gather for the prosecutor. With the one exception that you should blow at the station and give them two breath samples – or permit them to draw blood at the local hospital.
They are not your friends, as I have stated again and again, and are not going to give you any breaks. Keep your mouth shut except for “name, rank and serial number,” etc. Do not speak with the police. Do NOT take their 30 or 31-question DUI Interview at the police station. Control your urge to apologize, which can been seen as an admission of guilt. Do not make small talk and be friendly or conversant; it will not help you. Force yourself to not do it.
Tell them over and over, like a broken record repeating itself: “I am not talking with you.” Or, “I respectfully decline to make any statements.” Or, “Officer, I am invoking my Fifth Amendment Rights – to remain silent and not self-incriminate.” Be smart, but be polite until your attorney arrives.