If the confidential pricing is from the sticky in this forum, then yes, it is accurate. Be sure to add destination ($825), regional advertising ($300 in NC, not sure what it is in CO), and training ($180) to the invoice price. These fees are charged to dealers by BMW and aren't dealer add-ons. Other fees, well, that's between you and your dealer. Some states regulate the type and amount of extra fees that can be charged. I've never purchased a vehicle in CO and don't know about fees there.
EVERY price is "fixed." It's "fixed" when you sign the purchase agreement for a vehicle. How you get to that point will be different for every combination of customer - CA - vehicle - dealership. A reasonable place to begin would be the invoice price plus fees above plus some amount for dealer profit. An interview with the new BMWNA chief suggested the average dealer overall profit margin is around 2.5% but he did not indicate if that margin represented the profit in each car sale. Most posts on bimmerfest suggest invoice + mandatory fees + 1% is a reasonable deal. Again, though, that depends upon you, the specific vehicle, the CA, and the dealership.