I just finished responding, and it lost my text. Amex-Zag also provides a great buying-trend analysis that let's you know if your local dealers are within good pricing or not.
Obviously ---- packages and specific prices need to be evaluated because you're using a third party site from bmw as well as from a bmw dealer.
needless to say ......very reasonable quotes.
Yes, the prices/offers are with respect to invoice.
The dealer I actually bought from was not from Amex-Zag, but the reason I bought from him was his clout (one of the largest dealers on east coast), his personable nature, and the fact that he beat my local dealers from the start, enough to make it worthwhile to drive 6hrs round trip in one day ......without any quote comparisons.
;o] let me know if this helps !