Groaning noise coming from below the rear of my Mazda CX-5 that is not reproducible. Although when I do hear it, it is getting louder.
What driving conditions? When going uphill? Downhill? In only a certain gear? Only at certain speeds? Idling in the driveway?
Maybe you ran over your brother-in-law last week. You might want to take a peek under there to see if he’s stuck.