If immigration or the police signals you to stop your car, you should do so. They can ask for your name, driver’s license, insurance and registration. Show them these documents if you have them. Always carry a valid form of ID even if you are not eligible for a driver’s license. Do not carry false ID with you!
You have the right to remain silent beyond giving your name. Your passenger has the right to remain silent, but it may be best to at least give a name to avoid suspicion.
If an official wants to search your car, they either need your consent or a search warrant. You can refuse permission to search your car, but do not interfere with police or ICE actions.
You can always ask if you are free to go or if you are under arrest. If you are under arrest, you have the right to remain silent.