just restore it back
anything will come back as new

if u hack it and it get a virus restore it and it will be like when you bought it then transfer all your stuff back on

Yes, you can use iTunes to restore your iPhone, it will change it back.

hacking your IPhone is introducing viruses the same thing!..lol
no you cant change it back, and no you cant keep any of the stuff you bought before its hacked.

hack it, and you will be sorry!..

Yes. updating your phone will remove all of the software that was downloaded. and you will have to re-jailbreak it. it should not cause any harm to the phone, it will just remove the unlicensed things.

To my knowledge none of the iphones have this capability (probably not what you wanted to hear). The best thing for what your trying to do is the Zune by Microsoft. It displays:Artist of song being played, any album art, name of album and name of song. You can set it to display all content directly on the screen of your Avic. You can store tons of content on the 30gb or 80gb version to play directly in your car. A lot of my faithful Apple friends **** anything made by Microsoft, but once they seen the amazing picture and sound quality produce by the Zune, they were sold. It’s Definitely the best MP3 Player for car audio.