Well, I was planning on keeping my 2007 Sentra for at least another couple of years, so buying a new car just to have a workable Bluetooth system with my iPhone 4 is out of the question.
And, if I can't put a new radio/bluetooth system in from Nissan, I may have to look at other options and just not use the bluetooth in the car. That's a shame because of the built-in controls, and the automatic audio management when I receive a call.
I'm really ticked off about this because a far lesser phone worked absolutely flawlessly, and my expensive iPhone has issues. This problem is widespread. Look at other threads, and you'll see the same pattern - "my older phone (even iPhone 3G or 3Gs) worked fine, but my iPhone 4/4s doesn't work." And we're talking about Toyotas, Minis, etc.
Can't see how all these automakers are at fault. Looks more and more like Apple made a change starting in iOS 4.x through iOS 5, and now a lot of people are having problems.