We recently went for a 7000 km trip. To get ready I did the usual like checking everything and replacing filters. The engine air filter was interesting. When I removed the old one the area under the filter was littered with peanut shells. I suspect chipmunks as we have a trailer and feed them. I wonder however how it is that they are able to get into the air cleaner. I would expect the entry to be screened or some such.