Ok, I just bought my wife a 2015 550 with 38k miles. Car seems to be in good shape and well cared for. What should I keep my eyes open for? Is there any special service? Preferred filters/oil? Was planning on 5-30 Mobil 1 full synthetic. What's the best OBD code reader? Hope I won't need it. I haven't followed BMW brand for very long, so is this car a princess or can it be driven and remain reliable without constant repairs? I can honestly say I have my concerns about twin turbocharged V8 on that auto transmission. Maybe unwarranted. Thanks!