Air filter BMC-TW80140
I have installed a BMC conical air filters with double air flow ,side & central. The special alloy grid is the same as used on F1 air filters.

The Airfilter box was removed (four bolts) from the Mass Air Flow sensor (see below) and an adapter was mounted.

I used an aluminium adapter  from K&N Item No: 6615011  (for Toyota) and drilled new holes to fit the Passat. Don't forget to install a rubber gasket. A strut was also mounted to hold the Airfilter.