Withnail and I
Withnail and I was an arty film released in 1987. Ace saw it at the cinema a few days before she was transported to Iceworld. She thought it was funny (although her friends didn't get it) and she fancied Richard E Grant, the actor who played Withnail. (PROSE: Independence Day)
Fitz Kreiner mentioned having worked at "the Mother Black Cap in Camden Town in the sixties". (PROSE: The Fall of Yquatine)
Behind the scenes
Withnail and I starred Richard E Grant and Paul McGann. McGann went on to play the Eighth Doctor while Grant played a webcast-exclusive Ninth Doctor in Scream of the Shalka. Upon the release of Scream of the Shalka, it was wryly observed by fans that "and I" had apparently regenerated into "Withnail".
Michael Pickwoad was the production designer on the film.
Both Richard E Grant and Paul McGann exist in the DWU, with the latter even starring as the Doctor in-universe, in one film in a short story.