Wiesler's car - a Wartburg - is in fact a model which wasn't produced until the end of the '80s (the rear lights revealed it).
Meanwhile the soundtrack contains sound of the old - two-stroke - engine, and -somewhat confusingly- at the exhaust you can clearly see the typical two stroke smoke.
The same(?), later production type (with 1.3L four stroke VW engine) can be seen in light blue, standing on the right in one of the first shots of Georg's street.
When Oberstleutnant Anton Grubitz meets with Hauptmann Gerd Wiesler in his office, he is wearing a ribbon bar for medals on his uniform. One of the ribbons is for the "Ehrenmedaille 30 Jahre Nationale Volksarmee" (30th Anniversary of National People's Army). The scene is set in 1984 but this medal wasn't issued until 1986.
When Dreymann is looking through his own Stasi observation files, the typeface used in the layouts of the forms is "Avenir". This typeface was introduced in 1988, whereas the forms were supposedly written in 1984.
Secretary Hempf's car is a 1980s stretch version of a Volvo 264. But
all the interior scenes are shot using a Mercedes Benz S-Class Pullmann from the time of the film production. In a short clip the Mercedes is also used for an exterior shot, when Grubitz enters the car outside the ministry building.
When Dreymann is putting on his tie before his birthday party with the assistance of his neighbor, Frau Meineke, he finishes the job by folding down and adjusting his shirt collar. In the next shot, his shirt collar is "up" once again and needs to be folded back down.
In the final interrogation of Sieland by Wiesler, he sketches the floor plan in about 5 seconds, and definitely doesn't have time to make the double thickness lines, markers for windows, and door swing arcs. It in fact looks like at least two different pencils were used in the final sketch. His final stroke before showing her the sketch is circular in motion, with no circles to be found in the final.
When Grubitz is talking to Wiesler in his office, he takes a fresh cigar out of a Humidor. After the next cut, only three seconds later, he is smoking and the cigar looks like it has been smoked for a longer time.
Christa-Maria and Georg's apartment is in Wedekind street in Friedrichshain, as confirmed in the DVD commentary. The buildings in the entire quarter surrounding Wedekindstr were part of a massive rebuilding project in the GDR, and were completed in the early 1950s. All of the balconies that can be seen while Georg is playing football with the children on the street, along with the ceramic work illustrate the particular Soviet style really clearly. However, the interior of the apartment and most of what we see of the building interior is what would be called 'alt bau', effectively 'old style' - the apartment has high ceilings, the stairwells have carved wooden balustrades and doors which clearly predate the 50s. When the Stasi men come through the front doors for the first time, you can see the interior of these buildings as they really look, in the next shot the style has gone back at least 40 years.
After publication of Dreyman's article in "Der Spiegel", Stasi Oberstleutnant Grubitz is on the phone with an army general. He says they were able to procure a "Lichtpause" (diazocopy) of the original article. When talking with the typography expert, the typographic examples shown are in red ink, like the original, and the expert says he could be even more sure about his analysis if the examples were in black ink. However, a diazocopy is not a color copy and has a bluish color.
When Wiesler goes to the observatory post in the uppermost floor of Dreyman's house he comes from the far right. His assistant leaves through the main door, which is probably the only entrance to the uppermost floor. In the other scenes Wiesler enters through the main door.
In the attic listening post, Udo once addresses Wiesler as "Hauptmann" which the subtitles translate as "Comerade"; however, hauptmann is Wiesler's rank: captain. The spoken line was like a formal "yes, Captain" rather than "yes, comrade".
The literal translation of "Das Leben der Anderen" into English would be "The Life of the Others." However, the pluralization rules for collective nouns are different in German than in English, so "The Lives of Others" more accurately conveys the sense of the German title and is thus the better translation.
In the first scene in the theater, a program clearly states the birthdate of Georg as 1939, but just a few scenes later he says he is preparing for his 40th birthday. As the action is said to take place in 1984, there is a five-year discrepancy. [Possibility: Georg says that he is 40 in an attempt to shake off the impression that he might be 50. Hence, he could very well be 45. That age would also be the same as that of the actor who plays him]
When Dreyman looks through the files in the Stasi archives, near the end of the film, he wants to find out what "HGW XX/7"'s real name is. The clerk flips through the card box to find Wiesler's card. Before he pulls it out, four cards by the same name of "Olga Wildenhain" can be seen, two of them even with a man's photo.
At the end of the film, when Georg sits in his cab watching Wiesler delivering mail, right before the end of the scene two people with reflective vests are visible in the background. Presumably they are keeping bystanders from entering the shot.
The goof items below may give away important plot points.
When Dreymann hides in the staircase watching his girlfriend coming out of the minister's car, he stands by an electronic switch of a design which is too new to fit with the time period of the movie. The same thing happens when Wiesler hides himself the same place after he has removed the typewriter. The switch is new.
The gray Zuk van used by the Stasi squad, which has a 2L I4 four stroke engine in reality, has the sound of a two stroke engine (probably a Wartburg/Barkas) when they arrive with it to (don't) find the typewriter at Georg's flat.