As the title suggests, in this type of vehicle, the engine is placed in the middle of the chassis, between the rear and front axles. From the side view, this will generally put the driver farther towards the front and stretch the body towards the rear.
From the rear view, since the engine is placed in front of the rear axle, the transmission generally has to go in between each of the rear wheels widening the rear end. This is partially why mid and rear engine cars have wide rears.