after upgrade to IOS5, streaming music doesn´t work in car audio system

The service icon on the car audio system has dissapear from the screen and some calls cannot be answered trought bluetooth system. Anyone knows what is happening? Everything is dealing with the car audio system is completely out after the upgrade to IOS5.

The car audio system is 1 year ago and the manufacturer is saying me that they don´t have new software to upgrade.

Best regards