A side-by-side recreational off-highway vehicle having two front wheels and at least two rear wheels, the vehicle comprising: a chassis having a front portion, a middle portion, and a rear portion; the front portion being coupled to the front wheels, the middle portion being coupled to the rear wheels, and the middle portion surrounding an occupant compartment having at least two side-by-side seats for a driver and at least one passenger (14,16); wherein the chassis includes frame members of rectangular cross section and frame members of generally circular or oval cross section (110, 112, 114, 120, 136, 138, 140, 144); an engine secured to the rear portion of the chassis; a transmission secured to the engine; a drive unit operably coupled to a driven clutch of the transmission, the drive unit drivingly coupled to the rear wheels; a plurality of body panels secured to the chassis, the body panels covering most of the frame members of rectangular cross section and leaving exposed a plurality of the frame members of generally circular or oval cross section; wherein the chassis includes a frame member of generally circular cross section along right and left lower edges of the middle portion of the chassis; a rear cargo box positioned above the drive unit and attached to the rear portion of the chassis, the plurality of body panels including at least one bridging body panel extending from the cargo box to between the engine and the seats; and a rear separation panel extending downwardly from the bridging body panel to proximate a floor of the vehicle between the occupant compartment and the engine, characterised in that the frame member of generally circular cross section along right and left lower edges of the middle portion of the chassis is visible below the body panels. a chassis having a front portion, a middle portion, and a rear portion; the front portion being coupled to the front wheels, the middle portion being coupled to the rear wheels, and the middle portion surrounding an occupant compartment having at least two side-by-side seats for a driver and at least one passenger (14,16); wherein the chassis includes frame members of rectangular cross section and frame members of generally circular or oval cross section (110, 112, 114, 120, 136, 138, 140, 144); an engine secured to the rear portion of the chassis; a transmission secured to the engine; a drive unit operably coupled to a driven clutch of the transmission, the drive unit drivingly coupled to the rear wheels; a plurality of body panels secured to the chassis, the body panels covering most of the frame members of rectangular cross section and leaving exposed a plurality of the frame members of generally circular or oval cross section; wherein the chassis includes a frame member of generally circular cross section along right and left lower edges of the middle portion of the chassis; a rear cargo box positioned above the drive unit and attached to the rear portion of the chassis, the plurality of body panels including at least one bridging body panel extending from the cargo box to between the engine and the seats; and a rear separation panel extending downwardly from the bridging body panel to proximate a floor of the vehicle between the occupant compartment and the engine, a plurality of body panels secured to the chassis, the body panels covering most of the frame members of rectangular cross section and leaving exposed a plurality of the frame members of generally circular or oval cross section; wherein the chassis includes a frame member of generally circular cross section along right and left lower edges of the middle portion of the chassis; a rear cargo box positioned above the drive unit and attached to the rear portion of the chassis, the plurality of body panels including at least one bridging body panel extending from the cargo box to between the engine and the seats; and a rear separation panel extending downwardly from the bridging body panel to proximate a floor of the vehicle between the occupant compartment and the engine,