You may find the information you need at this location.

https://www.crossfireforum.org/forum...ad.php?t=27031

My recommendation is to :
1 Always use a Fleece filter
2 The Mann filters have worked very well for me you can get them at:
http://www.germanfilters.com/
- specifically
http://www.germanfilters.com/slk320-...1247_2056.html
and select the 2004 Mercedes - Benz SLK320 fleece filter for the 3.2 V
3 NAPA also has these filters