The new Maintenance Plans show that the "Drive Unit(s) Fluid Service" is required after the first year, then good for another 3 or more (5 year service not listed). This is new as far as I can tell. Is there some kind of an issue recently discovered that out of the factory the drive units require fluid service after 1 year? Is there some "break in period" during which the drive units pollute their fluids more than later? If it's not changed, what are the risks? Are the older (than 1 year) cars affected and how?