Am thinking about putting a K&N air filter on my 2000 ML320. I have no experience with these filters and wanted to get some feedback. Has anyone used them on a ML before, what type of hp effect and gas mileage did you experience. Also, if someone, preferably a tech would tell me if there are any negative mechanical/warranty issues that I should be concerned about as well as your take on the K&N filters compared with the standard MB ones. Thanks