Looking for recommendations on which spark plug to use for my 2015 Optima 2.0 turbo. From what I'm seeing, the Denso 3501 and 5356 have been discontinued. I am having a hard time finding the NGK 1422. It looks like the Bosch 9625 and Champion 9409 will work. Dealer wants $25 pr plug, not a fan of that price. Thanks!