It should also be noted, IVI interfaces differ from the mobile interfaces found in phones and MIDs. Those interfaces are still designed with "captive attention" in mind. IVI interfaces cannot demand captive attention by nature. They are close, but the differences do matter. Thus anything that your run on your mobile device in the car will have to be designed for that purpose. You can still get away with running mobile apps in IVI environments, but it's probably not going to be optimal.
"Captive attention" means that if you are using your phone, your phone is naturally the only thing your attention is on. You are typing a number, text message, navigating your music or other menus, and doing so while looking at the screen.
In the car, you are briefly looking at the screen, touching something, and then re-focusing your eyes where they should be: ON THE ROAD. This is why a mobile environment for the car has to be designed with that in mind. The text must be large enough for you to read at a glance. Navigation must be simpler. Buttons must be large. These are some of the concepts in the OpenICE standard. For more information about what makes a good mobile enviroment for cars, I'll refer you there.
Most mobile systems are not created with this in mind. These systems cannot be run optimally in the car and that is one of the big reasons why many state laws require only "hands-free" phone use in the car (please, please do not text and drive...).