I'm afraid that I haven't heard that one TC but here is something that might stir the pot a little.
Apparently at age 71 Sir William was quoted as having said "With hindsight it is possible to say that the MK10 was a little too big"
I think the poor man was brow beaten and pushed up against the wall by continuous ruthless reviews for so many years, and at that age he finally got fed up.
You only need to look at the story of the Tucker Torpedo and how poor Tucker copped it as well.
The reality is, the mk10/420G was the finest car to come out of Browns lane bar none! and a lot of critics are just now coming to realise that albeit too late.
Charles