That question was to Shadowblack5oh. I installed an OEM version on my S550 but I don't see how a factory option could be install on the S650 without really interfering with maintenance.
I was under my 24 GT this weekend changing out the front valance to the Performance Package splitter and I didn't even see an area that it would install too with all of the under body covers installed.
Additional items that affect the application is the 3.55 gears option with out the auto stop/start function. My Mustang came with both auto stop / start and 3.55 gears and is rated at 16 MPG city. Look at a car optioned the same without auto start / start and you will see the difference.
I have been taking my cars back to the dealership for maintenance since I moved to this area 15 years ago without any problems. This weekend I just took the Mustang in for its first oil change at 1000 miles (996mi) and was able to watch everything they were doing and it cost $88.95. I have no...