A method and system modifies a user interface (UI) of a portable device in communication with an interface device, where the UI is projected by a human-machine interface of the interface device to a user. The UI is modified by the portable device prior to being output to the interface device based on customized style information provided by the interface device. The interface device may be a vehicle interface device such as a head unit or infotainment system, and the portable device may be a smart phone, media player, or other computing device capable of displaying graphical information.