There is a thing which you can buy from KPTechnologies to do that.They told me they also do the service to modify the stock system so that you can play videos without having to put it in park and have the emergency brake up. It's dangerous to watch videos while driving but I can see it being a popular modification.
Do you lose anything after doing that mod? Like having to wait for the nav to update your location, etc.You can go to those aftermarket audio shops that help people install custom audio. If they have the hack for your model they can do it for you. Unfortunately I don't know how to do it myself.