I've been wanting to upgrade my iPhone 3GS from 3.1.3 to 4.x, but I was afraid the iPhone 3GS and the Sony CDX-GT630UI car stereo would stop playing nice together.
I spoke with Sony for the 2nd time in the past month or so and it shows that the 3GS isn't supported at all. I'm not sure if I noticed this when I bought the unit last summer.
http://esupport.sony.com/US/perl/support-info.pl?template=&info_id=269
Sony says that there is a fix in the works for iOS4 or the iPhone 4 - the guy I spoke to couldn't keep it straight, but no ETA on when the fix will be available. Come on, iOS4 has been out for more than 6 months right? How long does it take? However, I'm not even sure if it's a Sony issue or an Apple issue. But they should at least post an iOS 4 statement. Or if is there on their site -maybe I'm missing -it they should make it more prominent on the site.
Regardless, I took the plunge last night. I have been seeing some apps that I wanted to purchase that were for iOS 4 only. Worst case I could use the ALT input jack if it failed.
Before I upgraded I decided to try my iPad running iOS4 and I found that I was able to plug in the CDX-GT630UI and play music in iPod Mode and Stereo mode just fine. I received no "device not found" messages and no skipped music.
So, I updated to iOS 4.2.1 on the iPhone 3GS, Firmware 05.15.04. After I finished up I took it out to the car and plugged it in……it worked.
I was able to navigate music using the head unit and by choosing iPod Mode and navigating from the iPhone. Also the Sony unit charges the device through the USB connection.
I tested again today and I am able to plug the iPhone into the stereo USB connector and make and receive calls and the music mutes itself when the call is established. I also tried using my Bluetooth headset and it worked with that too to make or receive calls.
Just thought I would share my experience.