I´m still waiting for several bespoke Pollmann funeral coaches, that were built in Germany. There are many impressive one-offs around and I could imagine at least some of them were used for movie productions.

For example: 1966 Cadillac Funeral/ Flower Car, Audi V8L, BMW 750iL [E32], Mercedes Benz 600 [W100].

Another thing I´m waiting for, is one of very few 1950s BMW 501/ 502 funeral coach or ambulance, but I doubt any of them have ever been used for filmings. Maybe I have a better chance with a Borgward hearse.

@Animatronixx: perhaps you can find out, if the Mercedes 600-hearse had a role in a movie, if you just ask the former owner GBG Battermann. Since decades it's the biggest funeral company in Hannover.