took my 2012 in for it's 1000 mile service. dealer said the rear diff has leaked almost a quart of oil. oil all down the exhaust and inside the carbon underside panels. needs a new flange and seal according to them. one part is on back order and other doesn't even have a release date yet. I've seen the TSB for the 2009-2010 diff leak, you replace the flange and seal. but why the 2012? any tranny gurus in here care to chime in?