2000 MERCEDES BENZ M CLASS Engine And Engine Coolingengine Problems

ENGINE RUNS ROUGH, IDLES LIKE IT IS GOING TO DIE, CAR SURGES FORWARD WHILE MOVING OR STOPPED, DASH WARNING LIGHTS ON/OFF, ROUGH GEAR SHIFTING OR WON'T SHIFT, ELECTRICAL PROBLEMS, GAS TANK/GAUGE PROBLEMS, LOCK/WINDOWS POWERED WHEN CAR OFF, DASH LIGHTING GOES IN/OUT, HEADLIGHT/BRAKE LIGHTS BURN OUT QUICKLY, ELECTRICAL, STARTING CAR ISSUES. THIS CAR HAS BEEN IN/OUT OF THE DEALERSHIP FOR ALMOST 2 YEARS. I BOUGHT IT USED WITH A "CERTIFIED PRE OWNED WARRANTY", CODES GO OFF AND THEY SIMPLY RESET THEM. THERE HAS BEEN A NEW CONVERTER, WINDOW REPAIR, WORK ON GAS TANK, SPARK PLUGS, AND NUMEROUS OTHER "ATTEMPTS". NOW THE WARRANTY IS GONE AND MY PROBLEMS HAVE WORSENED. I DRIVE IT OUT OF THE DEALERSHIP AND THE WARNING LIGHTS COME RIGHT BACK ON. THEY ARE USING PROCESS OF ELIMINATION AND I'M PAYING FOR ALL THE GUESS WORK! THE OIL MONITOR IS ALWAYS OFF, GET THE OIL CHANGED AND IT GIVES...