Standard air filter box question

[3000 RPM]

Hi folks, just a quick question...

I've noticed autos have a different lid on the standard air filter box than other models. Does anyone know why??

The auto air filter box has an extra portion on the left-hand side, I've looked on the inside and it has a hole going in to the extra part, but it's just an empty molding on the side of the lid. Is it to increase capacity of the box?

Manual air filter box

Air filter box on autos

 

[infinity]

I think its to baffle noise

 

[3000 RPM]

Thanks for the reply, I now have one on my manual SE+.