My experience with SMBMW was also bad.
My friend and I were both buying new cars. We decided to go to Santa Monica BMW since it is close and we figured we had nothing to lose. We told the guy that we did all the research so here is our price and if you say "yes", you will sell two 325's. After 10 minutes he agreed on the price, we signed papers, we gave him a check for the deposit (They were ordered) and it seemed like the deal is done. All of this took about 2.5 hours. At the end he said that he had to see his manager to get the final approval. After like 20 minutes he comes back with his manager and the managers says he has to add $500 to the price of the car. We said "no", we told him that we signed the papers, we gave the checks but he kept insisting that the price is not final until he approves it. We argued for like 15 minutes, and we just decided to leave. They did agree to only add $100 but we just walked away. We ended up being there for like almost 3 hours. I think their strategy is to make you wait and bore you to death, so you agree on any price.
We ended up getting our original price that we wanted at New Century BMW and it only took 20 minutes. Henry was the sales guy. He was cool.