OK, back to the drawing board. In the Prius (I had an '05 for two years), all models have a display whether or not they have NAV. That's not the case with the Camry, or Highlander for that matter.

update I took my car to the toyota and they checked the codes on my car.problem was people said i break up using the car bluetooth.no problems when i switch to my katana or use my motorola h700 headset.I use sprint.
they cant replace parts for the bluetooth and have ordered a new radio.hope this fixes my problem.I checked posts and find i am the only one with this problem.

Duane,

Let us know if it fixes the problem. Good luck!

update got new radio everyone says i am sound much more like myself when im not breaking up but still breaking up bad. go figure.............back to sprint next.when i drove 1800 miles away from lexington ky no problems but here bad in 80 % of lexington i break up with the car bluetooth but not on my phone alone or with my motorola h700 headset.
wish the bluetooth worked better but i can live with it not
working till it gets fixed.
every thing else works just fine and im happy with the car. **** happens

The microphone is by the overhead switch that toggles the light between door/on/off. I had the same issue and wrote up this after finally getting the problem solved:

Setting Bluetooth sound level on 2007 Camry Hybrid w/ Navigation

In my '07 Camry Hybrid w/ Nav, my Motorola V3 Razr paired fine, and I could hear people fine when using handsfree, but people I called were always asking me to speak up. I couldn’t find a microphone sensitivity control in the user menus. I called Toyota service and they told me how to bring up the diagnostic screen (a function reserved for the service technicians). There I was able to adjust the Bluetooth "send voice level". Following are the instructions:

-Turn on car power (doesn’t need to be started)
-Press Map button (hit I Agree first if needed)
-Press Silver “Disp” button (bottom right side of display – physical buttong)

-A kind of divided screen appears with “Display” on top and contrast/brightness on bottom. While this screen is displayed, do the following very fast:

-Alternately touch the screen under the Display line, then above the Contrast line. Keep doing that over and over until the diagnostic screen appears. If it doesn’t work, keep trying. It took me a few tries. Touch the top, then the bottom, then the top then the bottom, all very quickly. Using two fingers might be too quick, as that didn’t work for me. I used my pointer finger. There is no icon, you just have to stay under the top line and above the bottom line.

The System Check Mode screen appears
-Touch Menu in upper right
-Touch Bluetooth Tel Check
-Touch Hands Free Volume Quality Set
-Change the “Send Voice Level to a higher number (press the up arrow next to it).
-Get back to the main menu
-Turn the car power off (there’s no other way that I see to get out of the Diagnostic screen).

The “Send Voice Level” on my ’07 Camry was set at zero. I changed it to 3 (5 is max). I then called my voicemail using handsfree, left a test message, played it back, and my voice was much louder. I haven’t tested it on the road yet.

-Tom Walker, Littleton, Colorado

You can exit this menu by holding down the physical "display" button for about 5 seconds. This will "reboot" the nav system, bringing you back to the "I agree" page.

hello fellow tch owners,

Please provide solution for adjusting mic volume for NON-NAVIGATION cars.

I repeat mic adjustment for NON-NAVIGATION TCH

Thank you and have a nice day.

It works! Great Job. I asked my Dealer, last week he suggested changing phone!? I like my Samsung i730 PDA, now my wife (very honest person) can hear me well. Thanks.

No takers, darn!!! I asked the same question once before, but it seems no-one has been able to solve this with non-NAV versions so far...