The NGK DCPR8E plugs are a standard NGK plug used in many motorcycles. So even though NGK has decided not to take the liability on aircraft, these plugs are still readily available from auto parts and motorcycle shops. In fact for 6 years now I and many others have been purchasing these plugs at these stores, rather than from aircraft parts suppliers like ACS, etc. They are still the same plugs; you will just have to ignore the red X thru the airplane, and of course not try to collect from NGK if you hurt yourself using these plugs. To me personally it changes nothing.