Overview & Reviews

Though high-end vehicles now come in more shapes and sizes than ever, the midsize luxury sedan segment remains the heart of the luxury automobile market. Nissan's luxury division, Infiniti, has been around since 1990, yet it had no real presence in this key segment until 2003, when the V8-powered, rear-wheel-drive M45 was launched. Although it offered a credible amount of luxury and performance, the original M45's relatively uninspired design and cramped interior kept it from registering anything more than a faint blip on luxury buyers' radar screens.

The last iteration of the Infiniti M45, however, enjoyed wide critical acclaim. With substantially more space, a tremendous amount of technology and comfort features, and a bold, imposing exterior design, the last M45 was a high-tech powerhouse with plenty to offer midsize luxury car shoppers. Its performance capabilities were raised significantly due to things like available four-wheel steering, a precisely tuned suspension and strong brakes. Even though the V6-powered M35 represented a significantly better value and offered potent performance, the current M45 was a swift, stylish, superbly executed luxury sedan that should be considered with the contemporary top players in the segment.

The M45 was replaced by the redesigned M56 for the 2011 model year.

Most Recent Infiniti M45

The most recent generation of the Infiniti M45 was produced from 2006 to 2010. First-year models were listed as having 335 horsepower, with subsequent models rated at 325 hp. This was due to a change in horsepower measurement rather than actual output and thus, performance was unaffected. The M45's five-speed automatic transmission had manual-shift control and a sporty rev-matching feature that imparted a particularly lively feel to downshifts.

Originally, there were two trim levels: base and Sport. Even the base car included such items as leather upholstery, driver memory functions and dual-zone automatic climate control. Stepping up to the Sport netted you 19-inch wheels, a sport-tuned suspension, active rear steering and adaptive xenon headlights. Options included such high-tech fare as navigation adaptive cruise control, lane-departure warning system and a surround sound system.

For '08, the mildly face-lifted M45 gained the option of all-wheel drive and its M45x AWD trim level. The Sport trim was also replaced that year in favor of an optional Sport package on rear-drive base models, while the navigation system was given a welcome overhaul that included a hard drive and digital music storage. It remained unchanged before making way for the redesigned M56.

The Infiniti M45's interior was well appointed and well built, with firm seats that were highly adjustable, comfortable and heavily bolstered. However, the competition in this segment was pretty intense and the M35 wasn't quite as elegant and thoughtfully engineered as some of its rivals. The quality of materials was a bit uneven, and we found that the layout of the center stack controls wasn't as clean and intuitive as it could be.

In road test reviews, editors praised the Infiniti M45 for its explosive power, sharp handling and its bounty of luxury features. Criticisms of the M45 included overly intrusive road noise and complicated center-stack controls that were hard to master. Also, we questioned the logic of buying the thirstier V8, when the M35's V6 provided nearly as much power.

Past Infiniti M45 models

The first-generation Infiniti M45 was sold for 2003 and '04 -- there was no 2005 model -- and was basically a Japanese-market Nissan Cedric luxury sedan brought over to fill the gap between Infiniti's near-luxury G35 and the larger, technology-laden Q45. Engineered for the narrow streets of Japan, the M45's cabin proved too narrow to hold corn-fed Americans comfortably, and the backseat was scant on legroom for a car of its size. Even worse, the M's exterior design was bland to a fault.

However, it was fast. The original M45 was available only with a 340-hp V8 and rear-wheel drive. Combined with big 18-inch wheels and performance tires, the M45 delivered respectable handling. Equally important, the original M45 was equipped with nearly the same number of safety features as today's model.

Cheaply priced and available with most of the luxury features found on the larger Q45, first-generation M45s generally represent strong used-car values in terms of feature content and performance. For shoppers who like the car's combination of stealthy speed and luxury, and don't need a lot in the way of interior room, the first-generation Infiniti M45 could be a good match.

User Reviews:

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  My M45 - 2006 Infiniti M45
  By RobB - July 7 - 7:16 am

  This M45 replaced a 2002 BMW7series. It was $30K less with most of the features and higher quaility. The V8 is as responsive and the trunk will handle 4 golf bags. The electronics function better than the 7 series and the gps screen is the best I have used. The only down side is this car is not a car for the winter season in Michigan (go for the M35 all wheel drive) We spend our winters in Fla. so its ideal. To sum up , this car is like driving a sports car with room for a foursome.

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  What a fun car!! - 2004 Infiniti M45
  By Peter - June 28 - 2:16 pm

  My first car in this class and I wanted something reliable, which meant it had to come from Japan. So the choice with this or a Lexus, and I have no complaints. After having the car for almost two years I still say WOW! Fast, smooth, and great options. It took a little wile to learn how the options work...but after you understand they come second nature.

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  I luv my M45 - 2006 Infiniti M45
  By KillerM45 - June 15 - 3:00 am

  Ive only had my car for 5 days but I can say that this is by far the the best vehicle I have ever owned. The luxury of the care is second to none. All the options ( I own the premium edition). I would most definitely recommend this car to anyone who is looking is catagory of car.

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  Great Car - 2003 Infiniti M45
  By marshalldempsey - May 15 - 2:00 am

  This is a great car. It has style, power, handling and the interior is nice without being a luxury car. The controls make sense, the options are easier than the C class, which I also think is a great car. The Infiniti does not have the quirkeness: brake dust, strange HVAC controls, uncovered seat rail bolts.

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  Love this car - 2003 Infiniti M45
  By John Welcome - April 29 - 10:00 am

  After test driving a LS400 top of the line Lexus then visiting the Infiniti dealership, it was an easy choice. The dealership not only treated us more professionally, but had a superior product with a much better price tag. Loved driving this car its lots of fun. Ran a G-tech on the car and it ran 0-60 in 6 seconds and a quarter mile in 14.2 not bad for a four door sedan. If you are looking dont miss a test drive of this car. So far the only downside I noticed was that the controls on the side of the seat are not real easy to reach, however once the seats are set the memory seats are easy to reach.

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  the best - 2006 Infiniti M45
  By MIKE BISHOP - March 20 - 8:16 am

  I get great comments wherever I stop for gas or to have lunch. I have owned most of the top makes and this is right at the top.

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  2006 M45 Sport - 2006 Infiniti M45
  By Brettrun - March 12 - 9:33 am

  I have had this car for about two weeks now and it has been awesome! It replaces a G35 coupe and the difference in fit, finish and quality is amazing. I had two G35s and always was disappointed by the cheap and often squeaky interior. The M45 is a world apart in terms of materials and and the feel of quality. If anything, the car is faster too. There is no substitute for pure V8 power and torque! The list of technology and features on the car is a huge leap also. Especially if you love the gadgets like I do. I compared the Lexus GS and Acura RL and found the M45 to be the best choice for me. It is more of a SPORTS luxury car, but has all the features of the other two if not more.

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  Getaway Car - 2004 Infiniti M45
  By kevin 5 - February 27 - 2:00 am

  Car shopping last weekend, drove this with the dealer saleswoamn in the back seat. Impressively fast and nimble for any car, let alone a heavy one, I found it could comfortably double recommended highway exit ramp speeds w/o noticeable oversteer or tire complaint. The silent V8 had real thrust to adjust high-speed handling and accelerate from 100+ mph. As the owner of an 01 M Coupe, I tend to like odd-duck styling. My impression? This car is fun and off beat. (And probably superior to the E-class my father owns - he thinks so.) I was guessing this was what a Tokyo gangster must drive.

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  I love this car! - 2006 Infiniti M45
  By mbeirwagen - February 22 - 5:26 pm

  I have been driving luxury vehicles since 1995 and I am absolutely blown away with my M45. Once I understood how to run the controls which are a little intimidating, I have been on the ride of my life....Watch out for cops. The interior is finally luxury for an Infiniti. This is my 5th Infiniti and the others ones had a very plastic interior. Not this one! So much better than the GS 430. You really must treat yourself!

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  Its going to be a classic - 2004 Infiniti M45
  By Karl - February 3 - 8:13 pm

  Bought my 2004 brand new right after my BMW 540i came out of the shop, Again. It is an awesome car that is not well known. I took a BMW 530 to task with no problem. No one knows what this "sleeper" can do. Most dont even know what the M45 is. At 70 MPH this car is asking you to please let it go faster. At 100 MPH its asking to please open it up all the way. During that time it feels and handles like a German car and the stereo is going, so pay attention to your driving. If you cant handle or appreciate very fast cars, go get a something else. This one is a dark horse among many wannabes. At todays prices its a steal. They wont be so low for long.