Not true. Depending on how stingy your dealer wants to be, putting in K&N air filters can completely void your warranty. Any modification to the vehicles drive components that changes the engines performance can void your warranty. Example: A good friend of mine has K&N filters in his TL type s. One day his transmission started slipping on him, so he brought it to the Acura dealer to check it out. If it were not for the fact that I knew the service writer, the service manager would have voided the entire powertrain warranty of the vehicle because, even though these filters make the engine more efficient, "they add power to the transmission above what the transmission is designed to handle." Therefore, voiding the warranty. I'm not trying to discourage people from modifying these cars, just make sure whatever you do is reversible so if you do have a problem that could be related to what you changed, the factory stuff can go back on.