I mistakingly made an incorrect statement above - both my D90 and D110 have 4 grommets on the engine cover.

 

Update: After my disappointing last visit to the dealership, after which I discovered several engine cover grommets dislodged, and one missing, I called to inform the Service Advisor of their less than stellar workmanship. During that call he informed me that my A-pillar was finally in to fix the crackling noise at highway speed. (Only took 5 months to get the parts). So, I just returned from this most recent visit and decided to look under the hood upon arriving home. Lo and behold, as evidenced in the pics below, I discovered two grommets dislodged and one missing. It’s my belief that the mechanics are simply laying the cover on the engine and simply slapping each corner believing that will cause it to seat properly. Not so. The grommets are dry, the pins on the engine are dry and although most trim pieces using clips, tabs or inserts are simply snapped into place with an audible click, this method is not working for the engine cover. Other posters here have experienced exactly the same result, finding missing grommets after a trip to the dealer. My solution to this recurring problem is to place a tiny amount of lubricant on the receiving end of the grommet, and/or the pin on the engine, and ‘gently’ pushing the cover into its desired position. I used a little silicone based bulb grease, but anything similar such as silicone lubricant or even a small dab of Vaseline will do the job. I’m going to share this tip with the Service Manager and suggest he ‘retrain’ his staff in how to replace the engine cover without losing or dislodging the grommets. I simply don’t have the time to drive back there to have this piddly issue addressed repeatedly.

 

They tech should use a light spay of silicone, but they rarely do. I have experienced missing grommets with just about every brand of car that I have owned (Porsche, Audi, BMW, Acura, etc). It is not a JLR tech issue; it is techs moving too quickly to get the car out of their bay and prob 99% of luxury car customers never notice as they never look under their hood.