For certain it is market driven. Most folks will surely welcome the BMW 4yr/50,000 mile- maintenance included warranty also. But it is not the full story. The "scheduled maintenance included" is also included in the price. So in effect you might be charge FULL price UPFRONT for scheduled maintenance that is performed 1 to 4 years, or some miles, later. So a normal customer to BMW DEALER transaction would be paying the BMW independent dealer (at the time of the service) say 150 dollars for a scheduled oil change. Under the "scheduled maintenance included menu" now becomes a warranty issue and the dealer now submits a warranty performed action (to BMW, or whomever handles this for them) and is reimbursed at a much lower rate by BMW and parts at wholesale or below (say $55). Even unscheduled or warranty work components are built into the price of the vehicle (so are all others but...) This of course is seamless to the customer. Of course the reason why this works is because of BMW dealers usually charging far above most other dealers or independents for each line item of maintenance. So it might seem refreshing to a BMW customer to walk out the door with a free latte and just a sheet of paper detailing the service and "no charges". There are a lot of reasons why BMW is one of the more profitable mass marketed car companies.
So germane to the life long synthetic fluids: ATF and differential, it is unlike engine oil in that combustion contaminates are not part of the reason why you are changing the oil. In fact the only real enemies are normal gear wear and heat generated due to normal operation. So to me the real question is what you are really buying? If it were me, I'd define what lifetime is. So if you plan to keep the vehicle 200,000, 300,000 miles, by all means change every 100,000, as a periodic baseline type action. If you tend or plan to keep it like normal folks (8.5 years, 12-15k per year, why bother? Take the money you would save by not changing and take a good long road trip.
[ February 27, 2005, 02:01 PM: Message edited by: ruking77 ]