Automatic Bluetooth clock updater

When I’m in my car and my phone connects to the stereo system, the stereo should check in with the phone and update it’s clock as necessary.  The phone’s clock has to be synced to a proper NTP server so that it can view SSL-encrypted webpages, so you have to assume it’s going to be correct.  The car should ask the phone what time it thinks it is and then update itself accordingly.