The handsfree on my Nokia isn't that quiet

Mine is. Eg. it's impossible to use it in the car. I simply can't hear what the other party is saying. It's impossible to understand anything if the room I'm listening in isn't whisper-quiet and there is more than a two foot distance between the phone and my ear.
The volume is set at it's maximum.

I've also got 3.16. What is the latest firmware?
Is there a way to upgrade to it? I've looked at the Nokia site and found nothing.