Usually in the Renault Fluence is the right side of the torpedo. A solution to the problem could be a torpedo of silicon. Frequently unpleasant sounds come from the place of contact of the torpedo with the windshield. The problem is solved by installing the soft material between the torpedo and the glass.
It is also possible that the plastic amplifier of the body, which is in the air intake of the heater (under the windshield, under the hood), creaks. To make the sound disappear, you need to remove the cover of the air fence. You can see at once the bars (the osbodies of the body) that are recommended to be glued if the creak comes from them.