Hi,
I just received the air filters from Fastlane for my 99ML320.

However I'm a little confused:

A) The Mann engine air filter looks different from the stock filter in the car. It is 'stepped' on the underside, instead of being completely flat on both sides.

Click Here for a picture of the air filter

Now, my question is which side is the front (nearer to the radiator) and which side is the rear (nearer to the firewall)

I know that the flat side fits on top of the air box, but I'm just wondering what's the orientation on the underside.

My SECOND question is in regards to the cabin air filter. The cabin airfilter that I got from Fastlane is unidirectional - airflow is one way. When I put the filter in, which is the correct airflow direction - left to right or right to left?

Thanks