Bluetooth picking up when we don't want it to
 

I have a Samsung SCH-540 and i have an odd issue, that when i am on the phone and near/in the car, the car picks up the call. This is really frustrating because, at times i have clients in the car and i speak directly through the phone. In another instance, i was at the car wash and my call got transferred to the car while the car was being driven out.
Is there anyway i can control when the BT is picked up by the car?
I don't seem to have this problem with my wife's Treo.
Not sure if this is an issue with the phone or the car's BT.

Thanks.

I had the same problem with my Nokia 6310i and my Razr. I now have an Iphone and I can easily choose what I want to talk through when the phone is ringing.

Some phones have option for that, i have mine on let me chouse
so the cell will ring and the car too, but i will have a choice on the phone display to answer on phone or on BT