Plastic cover over engine

here are a couple of pictures of my solution.

that is a cover as a dress up item. it is put on there just for a sales aspect of the car. it may have a bolt and a few rubber to plastic connectors you can look on bottom for the rubber things one may be missing causing it to rattle or the where it connects to is broken off. pull the dipstick and look for any bolts that will screw into a bracket remove the bolts and the cover will come off then turn it over and look for either a broken mount or something similar. if you cannot see it send picture of bottom of cover and top of engine and maybe we can see it. it will not hurt to drive with out it just put dipstick back in after removing it. it is a dress up item.

Thanks for your help. One of the brackets was broken. Removed the cover.

Having said that, only some of the rattle went away. Low rpm (idle speed) rattle evident in drive and reverse. Goes away at normal driving speed, starts back at stop signs. If I put it in neutral, rpm increase enough that rattle stops. It still sounds like something is loose.
Drove to local repair shop. Of course rattle would not manifest.
Where do I start looking now?

It may be torque converter bolts have loosened up so you can have that checked, then check for loose shields under the car. also, check shield over catalytic converter they are riveted and they break on rivets then shield rattles. which may be more of a possibility.

Thank you so much. Back to my neighborhood repair shop. Hoped it was something real simple. I am too old to crawl around under the car and do not even know where to look for a torque converter. Thank you again.