Hello, unfortunately I found nothing in the R-class forum about changing air filters, except that it seems to be a bit complicated. Is there a guide on how to change the air filter, and whether the R-Class also has an activated carbon filter or an interior filter, and if so where it sits and how to change it. I would be very pleased about an answer. Many say hello to Uwe Ps: it’s about an R-Class 320CDI 4matic, Built 02/08