I ordered my car pre-production mid december 2015. The stock manager said he would probably call me around beginning of January for the final order. It is now going on mid February with no response. So---at this rate I cannot see production over 3000 this year. Just my opinion.
The GT500 motors were "hand assembled" also and there were nearly 11,000 of them sold for MY 2007 as well as some ordered and sold thru the Ford Performance Parts Catalogue. Be absolutely certain that Ford can build 60 some thousand dollar Mustangs faster than the public would ever consume them.