I bought this from Hertz Car Sales in 2019 so the vehicle had been used for 1 - 2 years. After a year and a half of owning this, I noticed a burning smell after parking my car or if I allow air to flow in from the outside. Another indicator is was the low engine oil light. The leak is slow because after parking it, it would have a few drops.

The smell is caused form the oil dripping onto the heated tailpipe. When doing my oil change, I noticed that the removable panel was covered in oil. I had two techs look at it from a hobby shop and the leak is way up in there that you can't see the source. In order to reach the source and fix it, a lot of parts would have to be removed. It would be labor intensive and I've been quoted at least $3000 to fix the issue. Had I bought this car brand new, I may have been able to catch this while under warranty.

I took it to another tech and he did some research. He said the Japan CX-5 assembly line had issues. The whole cylinder head and cylinder head gasket may need to be replaced. Based on the VIN, you'll be able to see where it was manufactured. I could keep driving this vehicle and just add oil whenever I get the indicator. I only recirculate the air in the cabin to avoid the smell of burnt engine oil.

Update from Dec 15, 2022: It turns out that the vehicle was still covered under the manufacturer warranty. I had made the assumption that it didn't carry over to second owners. The Mazda dealership said the leak was found at the cylinder head. They replaced that along with the gaskets. It no longer leaks oil and they cleaned off the residue as much as they could. What was left still left a smell for a couple of weeks but smell is gone now.