After much thought and tons of research I've hired Authority Auto as a car buying service. They are supposedly the best at getting the lowest price and handling every detail in the process. They negotiate the car price, accessories, service contracts, extended warranties, all of it and then review all the contracts making sure there are no mistakes or hidden fees.
http://www.authoritycbs.com

I've always done my own work and negotiating in the past but I don't have the patience to get the very best deal so I'm willing to choke down their fees and let them do the work this time and see what happens. They have tiered fees based on msrp and since what I want is over 80k they charge $1195. That's quite a lot but I figure at worst I'll break even from what I could negotiate and I'm looking forward to the white glove treatment. I'll let ya know how it works out, probably in a week.

Sounds like an advertisement. Nice try.

Sheesh, not at all. Check my other posts. I'm just a regular guy excited about buying my car and sharing my experience to help others. If these guys fail I'll blast them or visa versa. I'll find out soon if it was money well spent. Actually, they require a $200 retainer fee and then if you like their deal and buy thru them you pay the rest. Gotta love the internet.

Okay, I checked your posts. You wrote about 2,5 of them on this forum. Still does not prove anything, but if you really wanna give somebody $1100 - knock yourself out : .It's your money, you can do whatever you want

Doesn't sound like a terrible idea for a risk of $200. Let us know how it turns out!

Good luck with that..... I've always done my own negotiating ( 15 new cars since 1972 ) and ALWAYS come away under MSRP and sometimes by quit a bit! I can't imagine not doing it myself or PAYING someone else to do it.

MB of North Olmsted in Ohio always seemed to be a great deal. I walked away on my wifes vehicle for invoice and included the remote start. I would start with your dealer first, then shop other dealers.

I was in FL last year and seen 3 cars from the North Olmsted Dealership, 1 in Orlando and 2 in Naples... but as they say about FL... the more south you go, the more north it gets...

So, three weeks have gone by, any feedback?

It's going extremely slow, very frustrating. Best deal they could find in my area of North California was $1500 off so we expanded the area to L.A. and found a dealer willing to go $3000 off. Then my rep got sick for a bit then the dealer rep went out for offsite training for a bit. I've been waiting 10 days now for a quote on the extended warranty and some accessory wheels. I'm not pleased with the delay so far. I'm getting close to cutting bait and doing it on my own like usual. I just want to order the freaking car, at this point I know I still have a 3/4 month wait after that with the Designo and limited availability options I want. This was supposed to be fun.

Update:
I would not recommend these guys, they're fired. After 5 weeks I still had not even ordered the car with no indication or communication when it might happen. Who knows how long it might have taken. I expected much better treatment and communication. My rep would call me once every two weeks saying he's still waiting for the dealer to get back to him. They also don't respond to emails. I sent 5 emails, granted only one had a question, but I never got a response from any of them but he did say he got them when I called. I expected a response when I finally emailed them to pull the plug but again nothing. I get the feeling they have too many clients and not a good relationship with Mercedes dealers or worse. What ever the reason, I don't care, as they totally failed to deliver expected services they tout on their site and initial communication. Also, it's not like I'm a tough or abusive customer, the exact opposite actually but now I'm irritated I wasted so much time and $200 with these guys.

If it sounds to good to be true than it is! you should be able to get up to 4k off msrp.

Which dealer in LA was willing to negotiate? Was it Keyes European per chance? Please PM me or respond here

Sorry, didn't find out which dealer it was before I pulled the plug on the deal.