First, determine if you car really has bluetooth. The phone button on the steering wheel is NOT proof of bluetooth, as they all have that button. Look for a "pairing" button on the center console underneath the armrest.
If you have the pairing button, you then need to have your car's 4-digit pairing code.
If both are true, then put your phone in pairing mode, hold down the button for 3 seconds and then while continuing to hold the button, turn the ignition key to position 2. After three more seconds, release the pairing button and the car should then be discoverable. After your phone finds it, enter the car's pairing code.