I have been told by a european auto mechanic that I should not use just any synthetic oil. They tell me to use high performance BMW german oil. Is this better? Which is the best? I have been told by a guy I know that drives a 99' M3 that Mobil makes the best synthetic oil for european engines. Also, why the hell would anyone charge over $100 for an oil change, like all the european mechanics I found charge. Doesn't the oil cost only a few dollars more per quart?