A vehicle chassis assembly includes a frame assembly having a plurality of frame members connected together, a drivetrain, a suspension system, and an exhaust system. The connection of the frame members provides a low-profile configuration for reduced step height and a kick-up portion to allow ascent of steeper inclines. The frame further includes an exhaust pipe supported within a frame member and two castings bolted to removable wheel arches. The exhaust pipe has a circular cross-section that changes to a rectangular cross-section near the back of the chassis assembly.