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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  Performance and Value - 2006 Infiniti M45
  By Howard - June 17 - 5:30 am

  I am at the end of my 39 month lease and only have great things to say about this car. The acceleration is intoxicating. The sport package makes this car handle like a sports car. Great turning radius and people all the time comment and ask if the rims are aftermarket. These are the nicest factory 19 inch rims out. Pearl white paint glows and the interior is top notch. The seats in the sport package give just the right amount of support and navigation system works well. Overall it looks like I will soon be driving another one there is nothing out there I like more and it has had perfect reliability.

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  A great car - 2003 Infiniti M45
  By davidce - June 5 - 10:00 am

  I actually look for excuses to drive this car. Awesome power, unique looks, and it feels rock solid. The car gets a lot of looks. People dont know what it is. It looks like some exotic, exclusive, expensive import(which it is, except for expensive). The car really hauls. I totally dusted an Audi A6 2.7 Turbo yesterday. Just ran away from him. The guy looked really demoralized. He probably went back to the Audi dealership today to complain that his car wasnt running right. Anyway, the M45 is great. I used to have a 2000 Lincoln LS. It was a good car, but the M45 outshines it. Im very pleased with my choice.

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  drive in style - 2003 Infiniti M45
  By martyrie - June 1 - 9:20 pm

  what a ride, i love everything about it, most room ive ever had in a car (im 64") just a classy ride

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  Japan made a good sport sedan - 2007 Infiniti M45
  By ignacio garcia - May 16 - 4:00 am

  After researching several cars in this class including the BMW550 and the Lexus IS350 and others, I selected the M45Sport for its handling and value. Two problems for a 65 year old like me are: 1) Stiff ride for long trips. 2) Road noise. Gas mileage is another problem. Toyota has the technology backwards: If you want the sensing of front traffic while on cruise control or lane change notice, then push a button not the other way around. Excellent car overall.

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  myinfiniti - 2003 Infiniti M45
  By ksleps - April 18 - 10:00 am

  The car is great...ergonomics are a little off, dashboard tends to make it resemble a mimi-van. Great pick-up and nice ride.

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  Car of the Future - 2006 Infiniti M45
  By Infiniti - March 24 - 2:50 pm

  Most comfortable and stylish car I ever owned. Performance is there every time you hit the accelerator. No need to take your eyes off the road because everything is voice activated, including blue tooth celluar phone service. Plush leather interior and 19" low profile tires. 14 speaker Bose sound system. Ive owned Buick, Pontaic, Chevrolet, Volkswagen, Oldsmobile, Plymouth, Caddilac, but this is the only car that Im still excited every day I get behind the wheel. The only thing that makes having this car more pleasurable is taking it back to Ray Catena for scheduled maintenance. They give you 5 star service and treatment.

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  m45 - 2007 Infiniti M45
  By rmelli - January 18 - 1:40 am

  I have the M35X not the 45. I find the 6 to be big enough to get me out of any tight spots without any requirement for a larger engine. The car is a wonderful machine. I had to get used to the dash system, but once mastered it became very easy to navigate. I look forward to driving this car as it handles like a dream in the curves an open road. I have owned two Lexus a 2001E and 2000G. Both were wonderful cars but I like my Infinity best of the three.

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  An unexpected purchase - 2003 Infiniti M45
  By DMZDAVE - January 11 - 2:00 am

  Went to the dealer to buy an FX45. Drove this just for comparison. The FX is still there, the M45 in our garage. Ive owned 2 Corvettes, a Roadrunner, GTO, a 442 Olds, a Trans Am and a Turbo Mazda. Only a couple were faster, but this car is unbelievable. Smooth, Quiet, comfortable, powerful all in one car. (It has surprised several Mustang GTs and an S2000 Honda owner on the freeway on-ramps.) What more could you ask for?

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  The right choice - 2003 Infiniti M45
  By steve bxxxx - January 11 - 2:00 am

  Very pleased with my purchase. A dream to drive and nice not seeing one on every corning. Still a rarity on the streets. Well put together as you would expect an Infiniti to be. Traded in a 300M for better handling and got more than I could wish for in this size car.

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  Understated - 2003 Infiniti M45
  By Aray - December 12 - 10:00 am

  This car is an excellent value. More bells and whistles than both my 2000 E320 and my wifes 1996 E420. Blows both of them away. When I got into my E320 after two long days of driving the M45, the Mercedes seemed frumpy and outdated - and thats a car I love. The Mercedes handles better and burns less gas. Other than that, there is no comparison - the M45 is simply better in every other category.