On the new car market:
AU1 - its looks when compared with the VT in 1998. Repelled loyal customers and the way it was marketed was a fundamental misread of the market for which quite a few executives left... We all know how robust and legendary they proved to be however.
XK - front suspensions busting, not a good initial impression.
EA - quality control
As they aged:
BA - control blade rebuilds, quality. How the interiors have aged. When new the BA was exciting and perception was that it saved Ford with its style, power and inclusion of lots of tech like the DOHC and
IRS... It will still go classic and be remembered as one of the best however, because of the Turbo...
Stuff like the Territory never getting a real fix for the tailgate rust deserves a mention too...