Charcoal filters . . . there's two!
As I recall, the pre-filter get serviced at 90K or 100K miles. But don't recall seeing anything about the main filter.
Just changed my S500 charcoal filters (95K miles); the pre-filter, which is easy, cost about $100.
And the main filter. This is difficult to get out. Cost also about $100.
But no stink! The prefilter was very WET because the air plenum drain hose got diverted and drained into the the pre-filter cavity. It had a damp smell but was not detectable in the car.
Good luck, it's a job.
Regards . . . . JimF
'94 S500 Cpe
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