I went with AFE cone filters instead of the flat panel type with no issues whatsoever. I believe that one particular problem with these type of filters is the amount of replacement oil used when cleaning them. Too much oil may lead to serious problems. I have cleaned mine at the 20k miles mark and used the recommended amount of AFE oil to make the filter effective. I won't change the filter oil for another 30k miles. At the same time as cleaning/re-oiling, I clean both MAF's.