A removable panel system for easily and efficiently varying the configuration of a cabin on a vehicle. The removable panel system generally includes a vehicle having a cab defined by a frame. Different panels may be selectively and removably connected to the frame to form various different cab configurations to suit the different needs of different jobs or operators. A roof panel may be removably connected to the frame to form a roof of the cab. A rear window extension may extend from the roof panel to form the rear window of the cab. A door receiver panel and/or door panel may be removably connected to the frame to form one or more doors of the cab. A windshield panel may be removably connected to the frame to form a windshield for the cab. All panels are adapted to be easily and efficiently interchanged without undue effort from the operator.