GolferGal,

If you have Cingular service, you will hear your phone interfere from time to time. It happens on most amplified stereo systems... home or automotive.

It's actually the cell phone interference hitting your amplifier and/or speakers... I've just learned to tune it out.

If you are not with Cingular... you can find out if it's your phone by turning your phone off when you drive the car (presuming you're not expecting any important calls). If you still get the static, it's not your phone.