Flex Your Rights has put out an excellent video on how not to get arrested. Below the cut, I've written several notes on how not to get arrested during a traffic stop (gleaned from the video). The 45 minute long video also covers how not to get arrested while on a city street and when police are allowed to search your home. Basically, it comes down to knowing a few amendments in your Bill of Rights:
4 - Unreasonable search and seizure: you have the right to deny a request to search your belongings, person, and property when no warrant is presented.
5 - Self-incrimination: you have the right to not self-incriminate yourself. In other words, never confess to committing a crime.
6 - Lawyer: you have the right to a speedy trial and the right to have a counsel (lawyer) for defense.
The video, while long, is definitely worth viewing. Even if you have nothing to hide, these are important rights that you should not give up. I say this below, but I will state it here too: people died for these rights. No matter what your stance on war, you must surely know that people have gone to war to protect these rights for our populace. Do not throw these rights away at the request of a police officer. To do so would be a grave disservice to you and would waste the efforts that people, both military and civilian, have poured into protecting our rights.
1. Do not confess to the officer. Even if you know you were speeding, don't tell them. Ask the officer why s/he pulled you over. Do not admit to a crime. Admitting to the crime waives your 5th amendment right against self-incrimination.
2. Don't make yourself an easy search target. If the officer asks you to exit the car, roll up all windows and lock the doors. It's your car, and you are protected against unreasonable search and seizure by the 4th amendment.
3. Contraband + Consent = Arrest -- These tips here are best to be followed by someone who has something to lose by having their car searched. However, I still agree that everyone should be following these tips, because even innocent people should not allow their rights to be trampled. The Constitution and the Bill of Rights were written for a reason. People have died defending these documents; will you now give up these hard won rights in a matter of seconds? If you do have anything to hide, these rights prevent you from being unlawfully targeted. Without a well-founded reason (something more than "these nervous teens probably have drugs in the car"), police cannot search your items unless you allow them to do so.
4. "Police are not paid to keep your secrets. They're paid to find, arrest, and help prosecute you." Again, do NOT confess anything. Remember mirandizing -- anything you say can and will be used against you in a court of law.
5. "Are you detaining me, or am I free to go?" Do not wait for the officer to say you can leave. Do use with discretion lest the police officer decide that he IS detaining you.
6. "I don't consent to any searches." This makes your stance clear, and it lets the officer know that you know your rights. Using the phrase "any" searches makes it clear that you will not agree to any search whatsoever and are thereby using the 4th amendment to protect yourself.
7. Don't complain about your ticket, especially if you got off easy (those with drugs in the car, this goes double for you). Accept the ticket, sign it, etc. Signing is not an indication of guilt. If you think the ticket is undeserved, fight it later in the court of law. During the intial encounter, just accept it. Remember: traffic court > criminal court
8. Police do not need a search warrant if something is plain view. For your own sake, don't be smoking your pot in the car -- have it put away in the trunk or otherwise completely out of sight. A police officer cannot search your car because he has a hunch, but he can search your car if he sees something illegal in plain view. Consent also makes the search legal. If the police officer illegally searches your car and finds contraband, your lawyer can file to suppress the evidence. However, the judge might not always agree, so it's better to ensure that the police officer does not search your car. (How to do so? If you get out of the car, roll up the windows and lock the door. Harder to search when they can't easily get in the car.)