I need to replace my 4ft Heat diffusers- I'm getting new carpet installed in two weeks. Upon removing the old battered diffusers, it appears they were installed and then the old carpet was installed making it impossible to remove the old diffusers without taking the carpet up. Is this correct? My other question is: Where can I find 4ft Heat diffusers? Home Depot etc, have 2 ft diffusers- haven't seen 4ft ones. Any idea's? I would like to stay away from white but it appears that might be my only option!