My buddy ordered the "WK 5001" one and asked them about the production date possibility. This was the reply that he got:
"Glad to hear you received the part and all went well.
And Yes, that is the exact reason why I needed your VIN, as we are all about making sure you get the correct part required. In fact as per BMW application restrictions, this Fuel Filter is only good for a 335d from 2009 to 2010 Year Model and "Through 01/2010" Production Year...
- So in other words; this is good for 05/2008 Up To 01/2010 Production Date.