For those who have iPhone-friendly docks/inputs (preferably USB) into their head units... Anyone take their current iphone, installed iOS4 and tried to use it? Did it work? Did it not work? I got a Car Stereo (Sony GTX310UI) in my car and ran great on my iPod Touch 2g w/ 3.1.2 firmware via USB (plays, charges, controls iPod from headunit as well)... I'm hoping the new iPhone 4 will work as well, otherwise I'd have to start playing through headphone jack (analog, bleh) and not get the charging function, which in my opinion is almost crucial with the quick battery life these devices tend to have. Hopefully I get some feedback from all of you who hooked it up to your car or home devices that are iphone-ready. Really interested in hearing your experiences and suggestions. edit: my Sony GTX310UI was only 99 bucks last christmas on amazon, and was manufactured in late 2008, before the os3 existed, so this gives me hope.