yah, swap out the cabin filter and see if it helps. there's a DIY in the DIY section, lists all the filters that will work on our cars.
im using a Fram CF10157 in mine right now. it's one of those charcoal (?) ones. thing is super nice. where i use to sneeze a lot in this one area around my town, with the filter in my 09 and windows shut absolutely no issue.
pollen was really bad last spring.