I just bought my 04 m3 about month ago(drove 4000k). I already have the oil change light on(inspaction note before start the car is zero). I went to the dealership to ask what is going on. Cuz I have another 2 bmws but I know they are different than the M. When I bought the car the dealer(not bmw dealer) told me this car can just put in mobile 5w or 10w 30 full synthetic. However, the bmw dealer try to tell me this car needs specialized services, which includ Cathrol tws oil, bmw proformance oil filter and etc. Do I have to go with all bmw stuff? I know maybe I should but they cost me about $600 total... what should I do? or if any of you have better ideas that wont hurt my car. Thank you very much!!