Over on the Apple Support forums, we've noticed a large amount of users saying that their car stereos are no longer working with Apples iOS 4. update. Users report that after updating an iPhone (or iPod) to iOS 4, plugging the phone into the cars integrated stereo create errors indicating the device is "Not compatible".
The thread, which is just under 400 replies as of writing, has hundreds of disgruntled users. Apparently, devices using iOS 4 are not compatible unless the manufacturers bother to update the firmware on the head units, which seems highly irregular.
Users write on the forums:
"My 2010 Land Cruiser stereo will also not work with my i-phone now after upgrading to OS4.....when I have the USB plugged in and the phone rings...the i-brick locks up and takes forever to hard reset!!!"
"I'm having the same issue with my JVC KD-A605. Plays for like 10 seconds if that and then cuts out on me. I deleted all my images and the phone started playing again for a full day or so and then when i re synced my phone again the next day it wouldn't read it again."
"my iphone 4 does not charge, does not show warnings, does not show anything. it just sits there. the radio screen reads -unreadable-"
The problem affects many types of stereos, with some sites even warning against iOS 4 on their websites now before buying. Some users on the Apple forums have found various fixes involving restarting their phones and the stereos at the same time, hard resetting both the stereo and the iPhone, reducing the functionality of the stereo, or even buying a whole new stereo. Apple is yet to officially comment on the matter.
Have you had trouble with your car stereo and iOS 4? Let us know in the comments!