I am really glad that I discovered their online parts counter. I saved over $85 on my order today compared to what I would have spent at other online retailers. Their prices weren't the best on all the parts I was looking for, so I will be buying some other items elsewhere.
But, for OEM nuts, bolts and a lot of other BMW parts (light bulbs, motor oil, etc...) I can't find a better price online. They have a 20% discount on everything if you order online.
I ordered the low-viscosity brake fluid. Not ten minutes after I placed my order, a gentleman from BMW of Fairfax called me to inform me that they were no longer selling that and would be returning the money to me via PayPal.
He also informed me that if some of the parts weren't in stock, he'd send them overnight when they were back in stock.
I can't speak to their sales or service that actually takes place at the dealership. But, one of my friends who takes his BMW there has told me that they can afford to offer parts at a discount since they charged him so much to work on his car.
I will definitely be returning to price check and buy parts from them in the future.
The only negative is that the website isn't the easiest to use. So, I recommend that you find exactly the part and part no. you are looking for on a different website and then just plug in the part no. when you order.
BMW of Fairfax - Parts Online