Hello. I too was having the echo / breaking up problem with my 2008 400h & my 2008 Prius. I actually gave up on my 3G iPhone and bought a TreoPro to be able to make calls on the AT&T network. A friend of mine with a 2008 BMW could barely use his 3G iPhone. He stumbled on a fix that I tried and it seems to work!
I went into the Lexus / Prius service menu and set the incoming bluetooth, outgoing bluetooth and voice quality settings to zero. I set the bluetooth volume on the iPhone 3G all the way up as others have suggested. After this rather bizarre adjustment the iPhone works as well as the Treo Pro. That is, the poor reception areas are still lousy, but that is AT&T rather than the iPhone.

 

how do you set the bluetooth volume on the iPhone 3g?

Thanks,
Mark

 

Answered my own question, figured I'd post it here for future reference:

simply initiate a call on the iPhone using the bluetooth connectivity, then increase the volume (as you would the ringer or speaker volume, using the buttons on the side). This will adjust the "bluetooth volume".

This change is persistent; that is, it will not need to be made again until you update the firmware (apparently).

Regards,
mcukier

 

Thanks for all the info!
I have the same issue with my 2009 RX 400h. I did the bluetooth setting what You wrote above but I still have the same problem.
I have an iPhone 11 and it still doesn't connect to my car via bluetooth in the rest of the cases.
I heard there are bluetooth setting somewhere in the iPhone, after the phone can connect with "elder" devices. I looked for these setting but I didn't find anything.
Do You have any ideas or experience, what I could do in this case yet?
Thanks in advance for Your help!