Does anyone know off the top of their head that if I were to put a K&N air filter my car would it void the warranty?

 

...and to save you a search, no modification will "void the warranty" of your car. The worst that could happen is if a mod was found to be responsible for damaging a component, you no longer have warranty coverage on that component.

Google "Magnusson-Moss act" if you want to know more about your rights when it comes to mods.