A frame subassembly for a vehicle is provided that includes a one-piece hydro-formed upper side beam and may also include a one-piece hydro-formed lower side beam. The side beams extend from the front or grill area of the vehicle to the rear portion of the vehicle. The side beams are interconnected by A, B and C pillars. The beams are welded to each other through access openings in the beams and in and the pillars. The pillars are attached to the beams by welding through access holes.