I have a '08 WR450F that I noticed has started coming home from rides with one corner of the air filter way dirtier than the rest of the filter. On closer examination today, I found a hole in the air box on the front, right, lower corner where it is closest to the exhaust. I've never seen this before, but never looked either. Part of this hole has smooth edges like the hole is intentional and belongs there, and other parts of the hole appear melted like the hole was melted and definitely doesn't belong. Can't find a picture or diagram that shows this corner. Does this hole belong?