Compressor housing is pretty grimy, but I thought the blades looked ok (except for my finger prints!). Notice that the intake hose is quite clean as well as the lid to the filter box (I've never cleaned those). Here's my question: Can I carefully wipe of the filter housing and quit there? Or, do I need to clean more of the turbo unit? Why is it that the intake hose and filter box is clean and the compressor housing is not?Thanks,Eric