For those with a CCSB towing a 5er, I would highly recommend the Reese Goosebox and a 4" B&W Offset Ball. I have an almost 90 degrees turning ability and clear the rails plenty. The airbag in the neck of the Goosebox absorbs all the road, absolutely no chucking and no noise. The offset weighs about 18 pounds and takes a minute to remove. Tons of bedspace when towing. When I'm done towing, I just pull the offset and chain anchors out and put it in my storage under my backseat.