Most parts places are supposed to know better then to sell platinum plugs and what not for cars that aren't made for it. Problem is, Bosch and other companies are giving McParts better deals on plugs if they sell more platinums. Bosch double and quad plats usually get the salesperson a little comission too. The parts store IS able to get H9DC0's... you just need to ask them to order em. If they say they can't get them, they just don't feel like doing a special order.