One of my favourites, this. Always thought Sarafian was greatly underrated as a director - his work on I SPY, THE MAN WHO LOVED CAT DANCING and, of course, VANISHING POINT was superb, and it's a real pity he isn't better known. A lot of people don't like the ending of this film, but to me it's one of the best things about it, along with Hemmings' tour-de-force performance.
Btw the Hemmings book is a great read, though he barely mentions his work in Italy - sorry to say I picked my copy up in Soho Books a few years ago for about £6.99...