protect your rights
Right to privacy
Although the right to privacy is not addressed explicitly in the US Constitution, it is alluded to in the fourth amendment which ensures:
“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”
right to an attorney
The right to legal representation for those facing criminal charges is found in the sixth amendment to the US Constitution.
“In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury of the State and district wherein the crime shall have been committed, which district shall have been previously ascertained by law, and to be informed of the nature and cause of the accusation; to be confronted with the witnesses against him; to have compulsory process for obtaining witnesses in his favor, and to have the Assistance of Counsel for his defence.”
The right to have an attorney appointed for your defense if you cannot afford one was established by the Supreme Court decision Gideon v. Wainright (1965).
right to remain silent
You have the right to remain silent. This applies to both the driver and passenger of a vehicle. Most of the time, it's a good idea to ask the officer if you're under arrest or free to leave. If you are under arrest, it is typically wise to invoke your right to remain silent until you have proper representation. (Better safe than sorry.)
Remember to always EXPLICITLY ask for a lawyer.
1. Am I under arrest? (If the answer is "yes", then...)
2. I need a lawyer.
You don't need to explain why you need a lawyer - requesting one is sufficient. Do not subject yourself to further questioning.
Simply keep calm, remain put, and stay silent.