I just bought a 2015 CX-5 with 212,000 miles. Very quiet running engine, according to the carfax it had very regular oil changes. And of course Billy Bob didn’t bother putting the oil filter access panel back. The car is also missing the little one that goes toward the front (I don’t know what that is for), and it needs the panel that covers the lower passenger side access panel that covers the end of the engine. The engine has zero leaks that I can see.

 

There are several sites that show parts breakdown such as this one. Often the pictures are just crude sketches but if you google the Mazda p/n you can usually find actual pictures of the part in question to verify that it is actually the part you're looking for,
Splash Shields for 2015 CX-5