I'm replacing the air filters on my 2011 X5 to get rid (or attempt to get rid of) of a funky AC smell. The dealer recommended I get the two charcoal activated filters that install outside the cabin under the hood (64 31 6 945 586). However, they also recommended that I get a filter that installs directly in the interior AC unit (64 31 6 945 596). I'm assuming this is the filter for when the AC is on recirculation mode.

Does anyone know how to install the internal filter or where the internal filter is located? I could take it to the dealer to have it done, but I'd rather just do the install myself than waste half a day driving back and forth to the dealer.

Thanks.