I used the black box on my 2012 GT also, and it does a fantastic job. However, it takes a long time and alot of effort to apply, and you can't do it outside in the sun or the prewax and wax are difficult to rub off. For show quality I use the black box, but for a regular wash/wax job, I use a spray wax/cleaner that does a pretty good job on its own. Owning a black car and keeping it looking good is a bitch, but nothing looks as sexy as a black mustang after a real good detail/wash/wax.