Inside the Badenweiler plant, text on the danger signs are literally translated from English into German, e.g. "Don't enter" reads "Kommen Sie nicht herein" which you won't find on any German danger sign. A German danger sign would rather read "Zutritt verboten". Same on the information sign "Access to roof". Translated to "Zugriff zum Dach", which is like "grip to roof" - correct will be "Zugang zum Dach".
Sidney is meeting Vaughn at a gas station. While they talk, Vaughn is supposedly filling an Audi A4 with gas on the passenger's side. The Audi A4's gas tank filler is on the driver's side.
When the car with the bad guys blows up, there is no engine.
On the mission in São Paulo, Brazil, whenever someone speaks Portuguese the DVD subtitles say "[Speaking Italian]".
When Sydney steals the ambulance, the original driver is visible through the passenger side window. As Sydney pulls away, the driver remains visible while the van moves off frame. Instead of Garner driving the vehicle out of the shot, the camera crew just rolled right to get the appearance of the van taking off and the foley artists inserted a peal-out sound.
Roads in Germany don't have yellow lines running down the middle (German road markings are all white), indicating that the scenes set in Berlin were shot in the USA instead.