Your best offense is a good defense. Remember to remain silent. Make sure you don't assist the police in prosecuting you. Don't explain you only had two beers. Don't explain that you were only going a little fast or that you are almost home. Remember, without confessions or admissions, the police have a very hard time convicting people. Be firm but polite.
Remember that you are not entitled to agree to do what the officer wants, unless you get permission from me. Blame it on me: you have to do what I have instructed you. Give your license or identification card to the officer. Don't volunteer any information. Don't agree to ANY tests on the road. Don't submit to a search unless he has a warrant. You will not pass their tests, and you will not gain advantage by doing what he asks. You will only give him enough information to arrest you, prosecute you and possibly convict you.
If you have been pulled over and the police officer has asked if he can search the car? Do not consent to the search of your car, regardless of what he says. Be firm but polite. If the officer has a warrant or probable cause, he will not ask permission, he will just do it. If he does not, he needs your permission. That is why he is asking.
Answer the door, step outside and shut the door. Do not allow them inside without a warrant. If they do have a warrant, ask to see it and then read it to make sure it is signed by a magistrate or judge. Do not agree to searches. Do not answer questions about anything. Only tell them that you want to contact your lawyer and call one of us immediately. Even if we don't answer, you know what to do: don't talk to them! USE THE CARD! People make mistakes. For many, it happens when they interact with the police. If that happens, remember: