I was messing with an m3 last night and under wot in 5th gear I stared to misfire at 5500rpm and the car really lost power. I quickly jumped off the gas and the cel started to blink then stayed on. I checked vag and codes p0300 for random misfire came up and misfire in cylinders 1,3,4 also came up. The car runs fine and there seems to have no issue untill under full load at high speed. Any advise to we're to look first?