The way you pair your phone
with the hands-free system in your car depends on your car and the hands-free system in it. Check the documentation for your car or hands-free system for more info.
If for some reason you don’t have a contact named Cortana
created for you automatically, you can add one on your own. Name the contact Cortana
and use this phone number—555-555-9876
If this number doesn’t work, your mobile operator may use a different phone number for Cortana. Check the documentation that came with your phone or visit your mobile operator’s website to see if they have more info.
Cortana is available on phones with Windows 10 Mobile
in some countries/regions. Check to see which software version you have
and find out if an update is available.
If you're having problems using Cortana in your car with Bluetooth, your phone might need to use a different kind of Bluetooth audio connection. For more info, see the question that begins with "My voice isn’t recognized when using Speech…" in the Bluetooth FAQ for Windows 10 Mobile