 The frozen lake in Iceland that is the location for some car chases,  does not freeze very often naturally. This is due to its closeness  to the sea and its high salt content. When the filmmakers had  troubles getting the Icelandic lake to freeze properly, they  considered filming the car chase scenes on ice in New Zealand. To  rectify this situation the river that links the lake to the sea was  dammed and within two days the entire lake was frozen to a depth of  over 2 meters. Once they solved that problem, filming could take  place in Iceland as planned.