If ICE police want to search your car, you have the right to politely refuse a search and ask if they have a warrant; you do not have to consent to a search of your vehicle unless they have a valid warrant to do so.
Key points to remember:

Ask about a warrant: Always ask if they have a warrant before allowing them to search your car.

State your refusal clearly: Say "I do not consent to a search of my vehicle".

Remain calm: Do not resist or argue with the officers.

Provide basic information: You should provide your driver's license and registration if requested.

Consult an attorney: If you are unsure about your rights or are being detained, contact an immigration lawyer as soon as possible.

You can ask if you are free to go: “Am I free to go?”

You can say that you want to use your right not to answer questions: “I want to use my right not to answer questions.”

Don’t lie.

DON’T SAY and DON’T SHOW false or expired documents.