It's really not that bad. A few minutes on your back in the passenger footwell and you're all set. I didn't find the new filter all that hard to slide back into place. BTW, I went with the carbon filter but I don't really know if it helps with odors. I can still smell stuff like diesel fumes, skunks, etc. while driving.

Contrast the Crossfire experience with my wife's Infiniti G35x where the cabin air filter is a dealer serviced item and the Mercedes design doesn't look so bad. Infiniti made the filter all but inaccessible for the average person.