The USB port in my 2011 Volvo XC90 worked beautifully until iOS 4.2. Now I get the "iPod unreadable" message on my car stereo. I'm using the AUX port with the headphone jack in the meantime until Apple fixes this bug. It's not very practical for a car manufacturer to be updating their software every time Apple upgrades theirs. Please let Apple know if you also are having this problem. Or post if you know how to fix without downgrading. Thnx.