The venue of any civil action may be changed by order of the court in the following cases:
(1) upon written consent of the parties;
(2) when it is made to appear on motion that any party has been made a defendant for the purpose of preventing a change of venue under section 542.10 ;
(3) when an impartial trial cannot be had in the county wherein the action is pending; or
(4) when the convenience of witnesses and the ends of justice would be promoted by the change.