I second this motion. A command to disable/enable certain skins would be great. Skins which must be disabled could have a line in them saying /LOCKABLE, another_screen.skin or something, and then when the disable command is given, instead of the DVD screen loading when you issue "DVD" command, it loads the 'another_screen.skin' which could just have the controls to control the video being sent to a second screen for example, or simply have a message on that skin saying "DVD is disabled whilst vehicle is in motion".
It would then be up to the user to use phidgets or some other input device to issue the command to road runner when the hand brake isnt engaged or something along those lines. Or even use the GPS speed to issue the command when the car is moving.
Would allow RR to be used more commercially, where laws require this functionality.