My son drove the MO in a drivers training class last spring. He a good sized boy, 210 lbs., not fat just a big boy. Just at the end of the event they were doing some accident avoidance maneuvers and I guess the extra strain caused the seat bracket/frame to snap. He said it made a loud noise and the instructor was a little apologetic for the breakage, though it was no fault of his. Just a poorly designed part.
The break occurred in an area that's only about 13mm wide and less than 1/8" thick. I removed the seat and pealed back some of the upholstery to find the problem. It fitted back pretty well so I covered all the closely exposed areas with protection and then mig welded it back. Used some damp rags to keep the heat from transferring too far, and rounded up a fire extinguisher just in case. Would probably have been better to tig weld it, but I don't have one of those. So far it is holding up.