If this is true, this is an inexcusable embarrassment. 2015 Mustang target of -400 lbs. turned into +200-300 lbs.
News Item:
http://mustangsdaily.com/blog/2014/05/31/will-the-2015-mustang-actually-weigh-more/
Source (Steeda):
http://www.steeda.com/blog/2014/05/2015-mustang-product-development-update/
Steeda has the cars, the scales, and no reason that I can reckon to publish this if it weren't true.