Will an ipod touch 4g charge when connected to a car stereo via a usb connection?

I am going on a long road trip and i was going to take my laptop but know i don't want to risk taking it on the trip because something bad might happen to it, so i decided to buy an ipod touch. My dads car has a new stereo with a usb connection and a little sticker that says it is ipod compatible. The ipod already come with a usb cable and i don't want to buy an extra cable with a car charger that connects to the cigarette lighter. Will the ipod charge if connected to the stereo with the usb cable????