As someone who never has, and probably never will lease a BMW (just preference), in the Marketplace last month we had brokers with 11-13% off custom build slots.
Now: is that this car? Can they sell to SoCal? Is that available for orders this month? No clue. But if you do some research here (in addition to the great suggestions you already received) you may save a few more $$.
I would also read the BMW wiki here
The MSDs changed recently, and each one gives a smaller MF reduction than it previously did.