For sometime I've heard a vibratory noise that seemed to be coming from the driver's side of the headliner. I noticed a small opening surrounded by a plastic cover behind the driver's side grab handle. I searched all of the Volvo sites to determine if this was the source of the noise. I finally determined that it is a Interior Temperature Sensor and is described on pages 3-7 and 3-8 of my Haynes Manual. I removed the plastic covering and sprayed compressed air (canned air, not compressor) into the opening hoping to clean the fan. This did not work as the noise continues. Now, I'm trying to remove the unit. The manual advises to remove the grab handle. There are two covers on each side of the grab handle. I've probed underneath to remove the covers but can't seem to dislodge them without causing damage. Any tricks to removing these covers? Anyone else have this problem and actually do a fix?