Polo GTI paper+sponge air filter

[polo226kph]

Last week I went to a VW dealership to buy a new air filter for my 2006 Polo GTI, when the parts saleman handed me the air filter I opened the box and noticed that there was an additional sponge glued to the bottom of the paper air filter. The sponge is about 12mm thick and covers the whole bottom of the filter. The additional sponge with a large strip of glue must surely lower throttle responce & performance. The part number is the same as the original but with a "B" added at the end.

Any comment on this.