Im very good at changing my oil every 10-11k miles always b4 the car's light goes on for oil! apprently u need to change every 7500 miles and bmw is wrogn when they say 15k miles, the mechanic thinks the main bearing in the engine went. thats a 7-11k fix thats not a small chunk of change at all the car is worth 18 grand! I'll get a second opinion. Is there anyway to find BMW liable for this?