(1970, Peter O'Toole, Susannah York)

Tale of a brother's obsessive love for his sister, and controversial when released. It's set in Scotland, but filmed partly in Perthshire and partly in Country Wicklow, Ireland, which leads us to the appearance of a rather battered bus in 'Midland Bluebird' livery with the fictional registration VES284. We only see it from behind, but I believe it's a 1953 CIE Leyland Tiger PS2/14 with CIE body, reportedly withdrawn from Cork garage in 1969 and scrapped after filming. Clarification would be welcomed:

(thanks Stuart Turner)