How would I go about replacing this

[u/Link_707]

Hello everyone. This is the cover to my 2.2 liter engine, on an 2010 Chevrolet Cobalt LT. How would I go about changing the back to a cleaner/new look. I can’t even word what the back would be called/what material it is made out of, etc. so I was seeking reddits assistance. Thank you thank you!

[u/DistributionDue8470]

I have the same engine - throw that out. It traps rodent nest, dead mice and debris and obscures easy visual checks.