Own a 2006 Convertible. Common issue are rusted out support bars. Ford Canada wanted $1200 Canadian for each bar ($2400 before tax). Obtained a high quality pair of support bars from the United States at $844 Canadian total plus duty. If you own a 2005-2009 Convertible you likely need to check out this guy's web page.:
Replace your rusted support braces.
mustangsupportbrace.com