I have noticed that these cabin filters in the Grand Cherokee get dirty a lot faster than the 20k recommended replacement, by 10k mine are black and full of crap, just replaced the second at 20k. I don't live in a dusty environment just normal suburbia so I guess that is just normal. Anyway I saw the below TSB and the updated filter they are recommending for the diesel for diesel smell, the updated filter is full of charcoal. I don't have the diesel I have the V8 but I have noticed sour smell sometimes probably all the leaves and water laying around in there some where. So I purchased the upgraded OEM charcoal filter this time thinking it may help some of the general smell the HVAC can pull in. It was $30 shipped which was not much more than the paper OEMs if I remember correctly. Just passing on for the next time you buy them maybe one to consider.