Hi, My situation is: I have a car with a USB port which I use to charge my iPhone 3GS and play music (just plug it in with a regular Apple dock connector cable). Now I'd like to find myself a car holder which has a dock connector, so I can just connect the USB cable and slide my iPhone in whenever I want, quick & easy. To give you an idea: I'm currently using a Mophie Juicepack attached to the lower right side of my seat using some double-sided tape. That way I can just slide it in & out when I sit down in my car, without having to fiddle with the cables etc... kinda like a holster. So I came across this tomtom car holder, which looks pretty sweet to me, but I have a couple of questions: 1) is the USB a pass-through USB? or just power? (because I need it for music as well) 2) does it work without being plugged in to the cigarette lighter? 3) does it fit the iPhone 4 as well? Or do you have any other alternative suggestions? I'd like to know.