Just picked up my first Lexus - '06 GX470 w Sport Pkg.
I paired my Motorola Razr and made some calls. Speaker sounds extremely muffled - unable to understand.
Dealer said it was my phone. I need other opinions.

I have Blackberry and Samsung phones, but I stopped using my Bluetooth phone connection since everyone I call using it complains that they could barely understand me.

My wife uses a Razr with her 08 ES350 and it doesn't work well at all... It drops a lot of calls and more often than not it takes multiple connection tries before you can hear each other. I use a Blackberry 8830 with my 08 GX470 and in the ES350 without any problems.

I was having the same problem. Lowered the bass on system and improved the sound a lot on my end. I haven't had any complaints from other end and I have asked several people. Just a thought. I may be wrong, but I wouldn't think the phone should have that much effect. All audio is thru speaker and mic in car, not the phone, I think. But I've been wrong before.