When Lana and Paul are talking on the roof, a sign can be seen in the distance reading "The New Million Dollar Hotel" (ref. Wim Wenders' film The Million Dollar Hotel (2000) where the roof scenes are very important).
In a statement at a public screening Wim Wenders revealed that, just after _Don't Come Knockin' (2005)_ was delayed for a year, he found himself with plenty of time and the urge to shoot. He developed a treatment in just three days, and then they worked on the screenplay for three weeks and directly after that shot the entire movie in just 16 days.
Every member of the cast and crew received the same wage of US$100 a day.