What factory-scheduled service actually means
Scheduled maintenance is not a list of upsells. It is the specific set of fluids, filters, and wear items your BMW, Audi, Porsche, or Mercedes was engineered to need at set intervals, and doing it on time is the cheapest way to keep a European car reliable. Skip it, and the savings vanish the first time a neglected cooling system or a worn timing component turns into a tow.
Every manufacturer publishes a schedule. The trick is doing it to that spec, with the right oil and the right parts, by someone who knows the platform, instead of a quick-lube special that treats your Porsche like a pickup.

