As for where it came from, the people upstairs said a lot, but the landlord didn't accept it after reading so much. I believe the landlord is not sure about these answers!
I am also the owner of Reiz, and I have experienced this taste. According to the analysis of 4S shop, tires and air conditioners are more likely, but the internal circulation is also a bit smelly, and it feels like it comes out of the nose. Personally, I think it may be caused by the rotating friction of those belts.
But you can tell the landlord that the talent upstairs is right and will gradually disappear after a period of time.