It sounds we might have had the same saleslady. You can PM me if you want, but if her initials are L.S., then we did. I was ALMOST in the same situation as you (I bought my car from South Bay BMW as well). Here's how my situation was:
I negotiated for the car in person with L.S. Good experience overall... during negotiation she had written down the four squares on a piece of paper. Well, I told her at that moment that I wanted floor mats thrown in as well, and she wrote that down, then went to the GM to discuss the deal. Just as an aside, I paid $1,124 over invoice out the door (with my mats). Well, when she came back after talking to the GM, he had said, no mats because I was getting a steller deal that only the employees get
Anyway, so I negotiated the price without the mats, left the dealership, and waited for my baby to come.
I come back to the dealer to pick up my car, and she goes over our negotiated price again. She takes out that piece of paper she had jotted the 4 squares on, and says... "Ok, so you want $1,124 over invoice and it looks like we're throwing in the mats". She HAD FORGOTTEN TO CROSS IT OFF HER SHEET and completely forgot the GM had said "NO MATS". She had the mats sitting next to her when I arrived to pick up the car, and I got the mats with my car all by keeping my mouth shut. I guess I got lucky, but because she had it in writing on her sheet... she couldn't back out. Believe me, I was damn near ready to fight for them mats. I guess it was all principle, so I see your point.