I want to confirm that the oil drain plug requires a 12mm allen wrench. I've got a complete allen standard/mm set and it only goes up to 10mm. my local mechanic also didn't have a 12 and my local o'reilly auto parts store also only had them up to 10. Is it really 12mm or did I misremember the size? if my memory hasn't failed me, where do you get a 12 mm?