Gents,A newbie here. Got myself a 2nd hand 320i M (E90) few weeks back. Now planning to service my ride for the 1st time. Asking the sifus here, roughly how much extra/premium (% wise) does authorized BMW service center charge as compared to other BMW independent workshops. Since this is the 1st service since i got the car, contemplating whether to do my 1st service at Auto Bavaria/Ingress Srvc Ctrs or M1/Optimum Workshops. Maybe subsequent servicing at independent workshops.Any advice....