The last Marder III variant was based on the Geschützwagen 38(t) Ausf. M, a purpose-designed vehicle for self-propelled gun use, again armed with the 75 mm PaK 40 anti-tank gun. Ausf. M was the final variant of the Marder series and was a significant improvement over previous models, with its lower silhouette, sloped armor and much more functional fighting compartment. In this variant, the engine was moved from the rear to the middle between driver and the rest of the crew. Because there was no engine in the rear, the gun and the crew did not have to sit on top of the engine deck as in previous models.