I recently bought my daughter an 96 318ti and had very little time to go through the fluids so I ran to some independent oil change business. I told them of my situation and being uncomfortable but time was in short supply. I asked them if I could watch over them as they changed the oil and went through the fluids. My daughter was arriving and getting out of the plane, visiting with us for a day, then jumping into the car for a 12 hour haul-ass to get back to work.
They said of course, and when I mentioned about the unique oil filter the guy at the register said "I know all about them, and I know I have two left, so were good". That impressed me! I have faith in the businesses until they prove me wrong.
I'm sure if you've been going there for years, you trusted them before, and you should trust them now. Just make sure to tell them to keep their mustaches out of the oil funnel.
Krafty