Check out BMW ConnectedDrive... looks like THIS is the perfect CAR STEREO for the iPhone. 
http://www.youtube.com/watch?v=iaNALBJ39LA
http://www.youtube.com/watch?v=iaNALBJ39LA
I purchased the Pioneer Appradio. It's total garbage. I contacted pioneer and they actually had a rep call me back about my issues. However, he made it quite clear that my problems would not be addressed and that they would not be spending "that kind of money" to resolve the valid issues I had with the product. - If you want my entire review, go to Amazon and read the review. It's too lengthy to type up here.
I told the rep from Pioneer that bluetooth was terrible and that I should have the option to run the phone through the 30 pin connecter since it is plugged in anyways. The Pioneer rep said, bluetooth is what it was, and that they would never allow me to plug in the phone. I spent $399 for terrible bluetooth?
The pioneer rep said that the Appradio was nothing more than an FM tuner with a port for a backup camera and a touch screen. (he was trying to blame the falts of their product on the iphone) However, this means that this product is a ripoff if they are charging $399 for an FM Tuner and a touch interface.
They geniuses at pioneer also tried to blame their products FAIL on Apples API's however when I had previously connected my iphone to my trucks radio, it knew when the vehicle was turned off, and the iphone would stop playing the musing. Pioneer has not figured this out. So when you turn your vehicle off, the ipod/iphone continues silently pumping music, so you are never where you left off. (Plus I bet this has a draw on battery).
But the Appradio is so buggy that nothing is really consistent. Sometimes when I reconnect the unit (After being out of my car for 3-5 min), it has no idea where you left off and so you have to restart the iphone/ipod.
There are a ton of other problems with this product. I was going to keep it in hopes that they would update the devices firmware and the AppRadio app. However the rep from Pioneer told me that they would not spend the resources to address the lengthy list of issues I have with a product that is still in BETA
DON"T BUY
The perfect car stereo for iPhone, is where your iphone acts as a front panel.
http://www.oxygenaudio.com/
I'm using this radio for a few months now, and I love it. Here's a movie you can watch:
http://t.co/FNXFz9g
Wow I had the complete opposite experience.
>>I ran a parking brake bypass switch and can operate all functions of the unit while driving.(not that I do, but it is much nicer then pumping the parking brake three times)<<
I like this idea. How hard was it to run the brake bypass switch?
Check out BMW ConnectedDrive... looks like THIS is the perfect CAR STEREO for the iPhone.
http://www.youtube.com/watch?v=iaNALBJ39LA
Wow, thats alot of devices to plug into it. DVD,CD doesnt matter, im sre that headunit has video playback.