The iPhone 4S/5/5c/5S iOS 8 update is a big debacle this week. The update to 8.01 was pulled and then a tool was issued to set iPhones back to iOS 8. Before the update, there were a myriad of problems reported in Apple forums with all makes of cars pairing Bluetooth with iOS and USB connection glitches/bugs. Forum users have reported some fixes that work.
Car owners with iPhones with iOS 8 reported problems connecting with Mercedes-Benz, BMW, Mazda, Subaru, Jeep, Volkswagen, Dodge, Chevy, Honda, Acura, Lincoln, Kia, Hyundai and more A list of connected cars reported to have iOS 8 Bluetooth connection problems was reported by AUTO Connected Car News.
Problems with iOS 8 and in-car infotainment systems include, no connection via USB, inability to send/receive calls with Bluetooth, no-automatic pairing, calling of last dialed call and Bluetooth only from car call button.
Fixes revolve around clearing information and settings and starting over. The most popular fix is to "Reset all settings." Other fixes include clearing out all the settings from the vehicle, factory resetting of the iPhones, deleting, nuking and starting over. Detailed step by step fixes can be seen at AUTO Connected Car News.
It appears the problem is based on previous settings in both iPhones and car infotainment systems.
In the future, hopefully cars with Apple CarPlay will not have any problems because the iPhone connects by a lightning connector and does not require Bluetooth. CarPlay has been delayed by most car makers except for Hyundai.