Upon request show your them your driver’s license, registration, and proof of insurance. In certain cases, your car can be searched without a warrant as long the police have probable cause. To protect yourself later you should make it clear that you do not consent to a search. It is not lawful for police to arrest you simply for refusing to consent to a search.
If you’re given a ticket, you should sign it; otherwise, you can be arrested. You can always fight the case later in court.
If you’re suspected of drunk driving (DWI) and refuse to take a blood, urine or breath test, your driver’s license may be suspended.