air filter location

Hello BimmerFest Member... I really need some assistance. I've search all over the forum looking for a DYI on engine air filter replacement DYI. This is my 1st BMW, and I'm not too familiar with the engine layout. I'm looking for some directions, and that I can be sure that I'm making any...

I just replaced the stock air filter on my 2007 328i with a K&N filter, when I took the housing apart on the work bench, I noticed a fixed second filter molded into the housing. Does this filter ever get replaced? which means replacing the output side of the housing?

Hi guys Can find my way round most engine bays but I'm buggered if I can find the panel air cleaner box on my 325TDS. Anyone able to help? Ta. Tirade