I've used their Mercedes pricing 3 times (2007 CLK 550 Cabriolet, 2011 E 350 Bluetec, and a 2012 ML 350 Bluetec just last week). I found their pricing can't be beat because of the extra "factory money" you get from MBZ Corporate in Montvale, NJ. On the ML 350's, pricing is $500 over dealer invoice. Then you get an extra $3,000 directly from Mercedes corporate. The "Internet Direct Manager" pulled the trigger to trade one of their incoming ML's for the one I wanted that was in Pennsylvania (I live in Fremont, CA). Did that without ever getting my $1,000 credit card deposit, or my signature on deal terms.
The store actually *lost* money on my deal, LOL, even after factoring in the 3% "holdback" of MSRP, due to ignorant salespeople. First, I insisted on dealer invoice for capitalized cost (before $3,000 from Corp.) telling sales guy I've never paid over and never will - which is true - so he caved since the vehicle was already inbound! Their "lease return manager" previously emailed me the store would pay for the 2 remaining lease payments on my 2011 E class, after MBFS paid 4 months. That misteak alone cost them $1,178. (Then he didn't know how to search to find the configuration I wanted across the country, so changed salespeople.) The new guy quoted $1,500 to ship it using the over-priced car carrier service Benz uses for dealer trades -- but the invoice came in at $2,100 -- another $600 lost. So they sold my unit $1,778 under dealer invoice, which was below their 3% holdback!!! LOL! Store still had to pay flat unit commission to the sales guy for selling the ML on top of this. Sales guy, Glenn, is very nice. If any of you live in the US Bay Area and still want to buy or lease a Mercedes as a second vehicle to your Model S, let me know and I'll give you his contact info. Also caught them trying to mark-up the $795 lease return fee to $1,095 -- sorry, Charlie, no dice!
For me personally, I much prefer the factory-owned store model Tesla is using with a fixed price for everyone. With all the time I had to spend researching and haggling to negotiate the price of my new ML, I'm sure I could have closed another deal or two! I only leased it for 24 months until May 26, 2014, hoping my Model X #83 will be delivered by then or earlier.
I've used USAA's car buying service, but generally get a better price by negotiating directly with multiple dealers. They have some special discounts I can't beat with Mercedes, but their general pricing model can be beaten by the dealers. That being said, I highly doubt there will be any deal they can get on the Model S.
Using the buying service got me an additional .5 off the interest rate USAA was offering. Got an additional .5 off by allowing them to ACH the money out of my checking account (non-USAA bank).
I've used them for insurance and financing for the past 25 years. Occasionally get a better rate through one of the credit unions I belong to but most times, they are the lowest.
