A Support document on Apple’s web site reveals that some Bluetooth-enabled car stereos and accessories may require a firmware update for control and playback with iDevices.
Customers who are unable to control playback through Bluetooth, or don’t see song names, artist, and other information displayed on the car stereo, may require a firmware update for their car’s stereo, according to the Cupertino giant.
Apple confirms that iOS 6 supports the latest Bluetooth standard for control and playback - AVRCP 1.4. However, some car stereos “may require a firmware update to correctly support the Bluetooth standard,” according to KB article TS4483.
Advent, Pioneer, and other manufacturers have already announced plans to provide an update. Some of them already have one available, according to Apple. Which is why the iPhone maker encourages customers to contact their car stereo manufacturer “to see if a firmware update is available.”
Apple also provides “a partial list of affected car stereos,” which names systems from Advent, Alpine, Clarion, Kenwood, and Pioneer. See the full list on Apple’s Support site here