The SLK 320 (2003 or 2004) K&N filter part number is 33-2185. I called K&N and asked if the Crossfire required 1 or 2 filters. The tech assistance person said (paraphrased) "We don't make a filter for the Crossfire and would not recommend the Mercedes filter because it may not fit properly and may let in unfiltered air."

So, are K&N users sure the SLK 320 filter fits and how many are required.

Thanks in advance