I've seen several videos showing how to do different mechanical and maintenance tasks on the JK and noticed that there's a lot of of them where the plastic cover is no longer on the engine. I know on some it's for clarity of the video but is that cover really necessary in day to day operation? What purpose does it really serve? I don't know how much noise reduction it would offer but does it have anything to do with air flow over the engine? There was one on my FJ Cruiser too and I know a lot of people took them off and left them off on theirs.