I can also confirm that after cutting off the silicone flap covering the charge port, the Commuter fits snugly into the car dock. I suspect the Defender will be too large to fit. Here's a tip on getting a perfectly neat cut. Figure out where on the flap you are going to cut. I did mine at the thin part where it's designed to bend when you open the flap. Get some thick paper, magazine, or anything you don't mind scoring with a blade and put it between the silicone cover and a hard surface. Place the silicone cover face down on your scoring surface and bend the flap out so the neck is exposed for the guillotine. Use a sharp blade out of a utility knife (boxcutter) and place the blade gently on the part you plan to cut. when the blade is well aligned, firmly press straight down. While still pressing firmly down, use your free hand to peel the flap off. I found that it was already cut all the way through when i peeled off the flap. My resulting cut is perfectly straight and clean, and you can't see any silicone coming out of the charge port hole.