code said several misfires on #2 cylinder

[aloeffle]

Had several misfire codes of late. Happens especially in cold weather. Codes list multiple misfires 2/6/8/ cylinders, misfire in cylinder 4 and 7. Car runs like crap. Sounds like a clown car. If you restart the car, it runs perfectly. Indie shop said there is a directive from BMW about this. Said they need to remove valve covers, and get manufature date for rocker arms. If they fall within a specific date range, they all need to be replaced. Car won't pass emissions test (Wisconsin) as is. Is anyone famiiar with this directive. If anyone has done this repair, can you give me an idea of what the cost will be.