(at around 1h 45 mins) The Mourner's Kaddish, the Jewish prayer for the dead, is recited in the film using the modern Israeli Hebrew pronunciation. The version of the Kaddish that Kirsch would have known (and that his prayerbook would've contained) would have used the older Ashkenazic pronunciation used by German and Eastern European Jews. Instead of saying, "Yitgadal v' yitkadash," as they do in the film, they they should be saying, "Yisgadal v'yiskadash."
(at around 29 mins) The Monopoly play used in the picture is a recent one. Houses and hotels would be in wood at that time.
The police VW bug has early rear fenders/tail lights and engine cover but the vented rims and flattened hub caps indicate that it's equipped with front disc brakes and thus must be from 71 or later.
In the second half of the movie, the English subtitles are seriously out of synch with the German dialogue, making it very difficult to follow lengthy conversations.