I almost didn't respond to this thread, but since I'm up and feel that some FW'ers can benefit from my knowledge/experience, here I go...

I'm NOT going to tell you how great or sucky MB or their E-Class is. That is up to the BUYER to decide, and everyone has their own opinions (as you can tell by some previous posts in this thread. What I AM going to tell you is that MB's quality fell off a cliff, and then started a shallow climb out between 2000-2006. Starting 2007-2009, with a reshuffling of management (and after dumping Chrysler), MB's quality has improved by Leaps and Bounds (going from pretty much the "bottom of the barrel" in the "super-luxury" segment to #6 in various quality/reliability surveys/studies in 2009... with Lexus being #1 again of course). I have driven/owned a couple MB's in the past during their "sucky reliability/quality" period, and as such I vowed never to buy another MB again for as long as I lived (not that I've experienced any MAJOR troubles... but enough small ones to keep the car in the shop more than I would like). However, with their improvement in their management, quality, reliability, and the VERY reasonable prices on the 2009 E-Classes (thanks to the "perfect storm" of the financial crisis + extremely soft market for luxury cars + discontinuation of the W211 E-Classes + 2010 E-Classes already on the dealers lots and being sold + spike in manufacturer/dealer incentives due to low sales), I feel enough has changed to purchase 2 brand new 2009 E350's in the last 2 months.

As far as this deal is concerned:

1) The savings of "$10,000" as listed by OP is a SEVERE UNDERESTIMATE as to what you can get! While vehicle pricing differs from market and location due to market demand, supply, dealer stock (or overstock), availability of your desired color/configuration in your area, popularity of your desired color/configuration in your area, etc, I would say that you should be able to EASILY TAKE OFF $15,000-$20,000 OFF MSRP (depending on the configuration of the vehicle, and supply in your area). What's more, if you bargain hard enough, you can PROBABLY TAKE OFF $15,000-$20,000 OFF INVOICE!

2) If you're looking for a 2009 E550 or E63 AMG, the savings are even more crazy! I've heard of people getting up to $35,000 OFF FULLY LOADED 2009 E63 AMG's, which translates to under $70,000 (without taxes or licensing fees)! Discounts on 2009 E550's are less, but still better than the ones on 2009 E350's! But better hurry, as both the 2009 E550's and 2009 E63's are pretty hard to find now (people have been scooping these highly coveted vehicles like crazy for a while now).

3) Do your research BEFORE going to the dealer to save the most $$$! Edmunds.com is a good place to start. Also keep up with what manufacturer's incentives are available to the dealer (which can be found on Edmunds.com). Think of this as money you should AUTOMATICALLY expect the dealer to give you (although sometimes some "persuading" is needed). For example, Edmunds.com lists that there currently is $10,000 Market Support to the dealers to sell 2009 E350's (I'm assuming this was what OP meant by the "$10,000" in his title). So you should automatically discount the price of the car by $10,000 in your mind EVEN BEFORE you start bargaining!

4) Mercedes-Benz Financial is also offering 1.9% APR to finance your new MB purchase for up to 36 months (2.9% APR for 66 months). If you need to finance your vehicle, this is a very good deal! I'm not sure how good the lease rates are though, since I don't lease cars, but I do know that the lease rates are higher than 1.9% though.

5) The "American Reinvestment & Recovery Act of 2009" allows each person to deduct the full value of tax paid on the purchase of a BRAND NEW vehicle in their 2010 tax filing. The maximum deduction allowed is taxes on amounts up to $49,500. Since you should NOT be paying anywhere NEAR that amount for a 2009 E350, you can deduct the full value of tax on your 2009 E350 purchase on your 2010 tax filing. (Buyers that purchase a 2009 E550 or 2009 E63, this may not be the case since your purchase price will most likely exceed $49,500. Thus, you will only be able to claim a tax deduction on the taxes for $49,500 of your purchase price.)

6) Saks Fifth Avenue SAKSFIRST MasterCard holders can earn a $1,000 GC if they charge at least $1,000 of their down payment on their credit card! Limit 1 GC per person. Limit 2 GC's per household per lifetime. For complete details, read your credit card's Terms & Conditions. (I forgot to do this when I purchased my 2 x E350's, and am now kicking myself for not remembering... hopefully you don't make the same mistake as I did!)

UPDATE: So after 48 hours I called SAKSFIRST back and they did receive my paperwork and verified that all you have to do is spend $1,000 or more in "eligible" spending in the calendar year of 2008 or 2009 (whichever is the previous calendar year of your purchase). Now all they have to do is wait for Mercedes-Benz to confirm my purchases before they send out my GC's! Thanks so much ppnff01! MAJOR green for you!!!

And now, to rebutt some topics that are 100% sure to come up in EVERY Mercedes-Benz thread:

A) Mercedes-Benz SUCKS because they don't have "FREE" service/maintainence for the first "X" number of years! Yes, it is true that Mercedes-Benz stopped this practice a few years ago while a few competitors still continue it. However, what most people don't realize is that the cost of maintainence for the first "X" number of years is actually INCLUDED in the price of the vehicle! Just do a simple calculation and figure out how much it is to service your vehicle for the first "X" number of years. For example, for the 2009 E350 (and probably all other late-model E-Classes), the cost for Service A in my area is around $180, and Service B in my area is around $299 (I live in CA... it's expensive to live here). Since Mercedes-Benz recommends alternating Service A or B every 10,000 Miles -OR- 1 Year (whichever comes first), the cost for 2 x Service A's and 2 x Service B's is $958 for 4 years. So, for example, if you buy a comparable BMW that offers "FREE" service/maintainence for the first 4 years, you're saving about $958 over the 2009 E350 (however probably paying a lot more for your vehicle).

EDIT: BMW covers not only scheduled service on its cars for the first 4 years/50K miles, but also covers all wear and tear items (except tires, which are covered by the tire manufacturer) on the car, such as brakes, wiper blades, belts, coolant flushes, brake fluid flushes, etc... Hence, the value of BMW's 4 year maintenance program on the 5 series is actually about $3,500. This does not detract anything from this deal, however, and it is an excellent one!

B) Mercedes-Benz SUCKS because they cost so much to repair/maintain! As with all (or most) luxury vehicles, all NEWLY PURCHASED Mercedes-Benz vehicles has a 4 Year/50,000 Mile factory warranty. Anything major that breaks (excluding "wear-and-tear" items) is covered under that warranty (parts + labor). Mercedes-Benz offers an option to purchase an EXTENDED WARRANTY up to 7 Years/100,000 Miles. They also offer the option to purchase 3RD PARTY EXTENDED WARRANTIES (if you do not want to pay that much for a genuine MB Extended Warranty, but I would highly recommend spending the extra money for peace of mind). And as with any luxury vehicle, if anything breaks outside of your warranty period, you're going to have to pay and fix. Bluntly speaking, YOU ARE BUYING AN EXPENSIVE CAR, SO OF COURSE YOU SHOULD EXPECT IT TO BE EXPENSIVE TO FIX!!! It's not cheap to pay to fix Ferrari's, Lambo's, Bentley's, Rolls', or even BMW's... why would you expect it to be "cheap" to fix a MB?!? If you're worried about major repair bills, I would HIGHLY RECOMMEND buying a genuine MERCEDES-BENZ EXTENDED WARRANTY as soon as possible! Then after your warranty period... sell your car and buy a new one! (Either that or buy a cheaper car that is cheaper to maintain/fix, like a Toyota or Honda or something!)

C) Mercedes-Benz SUCKS because their quality sucks! I already addressed this above in the 2nd paragraph of this post. But just to add on, have you PURCHASED/OWNED a Mercedes lately (2007+)? Have you even read the consumer surveys (#6 in quality/reliability), quality studies, and done other research on them? Have you gone to various Mercedes forums (the most popular one is MBWorld.org) and read the complaints? A good 95% of complaints listed on those forums are from vehicles made in the year 2006 or earlier (at least on the W211 E-Class forums). There are very few problem posted about 2007+ E-Classes. That's because MB had so much time to finally work all the bugs and problems out (as well as shake up management and reorganize their strategy and focus to improving quality). Anyway, I'll let you do the research and you decide whether you want to "risk" buying a MB or not. If you do, then great! If not, then great! Someone else will be happy to buy the car you were going to buy anyway!

D) Mercedes-Benz SUCKS because they don't have all the latest gadgets/features! As with any vehicle, gadgets and features cost $$$. You want gadgets and features? You need to pay. Some features are reserved for the higher-class vehicles (like the S-Class, CL-Class, etc), so to get those features, you'll have to buy that model car. I'll be the first to admit that Mercedes-Benz sometimes is slow in implementing certain technology/features in their vehicles (like rear-view backup cameras), and that Japanese cars seem to have the most "updated" technological gadgets of the bunch. Well, what can I say... Japan are extremely good at producing quality electronics, NOT Germany (otherwise all of our digital cameras, camcorders, computers, DVD players, etc would say "Made In Germany"). However, realize that one area Mercedes-Benz does NOT skimp on is SAFETY... in fact they have been the pioneers of hundreds of safety and safety-related systems in automobiles since they've been in business! Many of MB's inventions are licensed and put in other vehicles today. And the first thing I look for in a vehicle is SAFETY. As for other technological gadgets, IMO there are enough to satisfy me (for the price of the vehicle). If you want the most "technologically advanced gadgeted car", then buying a 2009 E-Class is NOT for you... look to the 2010 E-Class (which is more expensive) or another vehicle.

E) I should buy this because it's such a good deal... even though I HATE MB (or I HATE the 2009 E-Class)! NO YOU SHOULDN'T!!! Put down the credit card and exit the dealership! Seriously, if you find yourself in this situation, you need to sign up for shopaholics annonymous or something! Do yourself a favor and think this through logically: A car is a MAJOR purchase (probably only second to your home). Why would you spend $30K-$70K on something you HATE??? Why not save that money and put it towards a vehicle you LOVE (like a BMW, Audi, Lexus, Toyota, whatever)... or even another MB model you LOVE (like a 2010 E-Class, C-Class, S-Class, SLK, ML, GL, GLK, etc)? Honestly, as good as ANY deal is... if you don't have use for the product, or if you HATE the product and won't enjoy using it, then that deal is WORTHLESS to you. Put that money into another product you want/need, or save that money in a bank and earn some interest on it, or invest that money wisely. All of those options are 110% better than buying a product you hate and hate to use... and will either end up not using it or selling it at a MAJOR LOSS later.

Hope this helps clarify some things.

EDIT: Updated SAKSFIRST Mercedes-Benz Promotion qualifications.

EDIT: Added #E.

UPDATE: I was just told that MBUSA lowered the market support this month to $8,000 (August 2009) from $10,000 (July 2009)... at least for the 2009 E350's (don't know if other E-Classes were lowered as well). Stock in my area is gradually running out, with the largest dealership around here only having less than 50 E-Classes left (90% base, 10% with P1, and only in Black or White) down from around 160 last month. They estimate these will be sold out in about 2 weeks at this rate, therefore they are "raising" the price on these cars and won't be as "flexible" since demand seems to have gone up (whether it's because of this thread or not, I don't know). I don't know if all dealerships are making similar changes to their policy or not (ie: MBUSA-ordered change or individual dealership change), but good luck for anyone who is still looking for a 2009 E-Class!