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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  M45 - positives and negatives - 2006 Infiniti M45
  By HAL - November 14 - 5:33 pm

  I traded my 911 carrera for the performance, quality and "room". Previous car was an m5. So far i have 2500 mi. Build quality appears good and there is plentiful space in the cabin. Very poor pdi. Glue all over the car and the rear deck spoiler was warped on delivery. It was replaced after the second trip with another warped part(?). Has to go back again. Performance is acceptable for a 4000 lb. Vehicle, but not great- its no m5.Fit and finish excellent. Dealer very cooperative and apolegetic for the problems.

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  My Infiniti M45 Sport - 2006 Infiniti M45
  By Miller - November 1 - 12:06 pm

  My black Infiniti M45 looks great. Its fun watching heads turn from pedestrians and other motorists alike as I drive past. A full year into the ownership experience I still look forward to getting behind the wheel. The acceleration and torque remind me of the muscle cars I knew from the 60s. Ive owned 2 of the last generation BMW 5 series. The M45 competes with them in performance, but beats BMW 5s in room, comfort, and technology. Voice recognition (my favorite feature) for the navigation, climate control, phone, and sound system are easy and intuitive. A backup camera is overkill in a sedan. My wife loves the air conditioned and heated front seats. M45 - Nice car!

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  The fast and the friendly - 2004 Infiniti M45
  By jarrettblue - October 31 - 10:00 am

  Yeah a corny title, but deserved. This car is a drivers and a passengers car (front passenger anyway). Very comfortable, stable, smooth, quiet, and fun at all speeds in everything other than snow and even snow handling is impressive for this RWDer. It gets tons of looks, questions - someone even said it looked like a Bently; but styling is probably the most contraversal aspect of this winner. Nothing compares to its value per dollar. Its a big car but doesnt drive like a boat. After a while, you forget youve got 15 feet behind you.

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  Beats everything out there... - 2003 Infiniti M45
  By bob23 - October 22 - 2:00 am

  When I read some of the "professional" naysayer reviews, I have to laugh. They obviously know nothing about real-world ownership. I shopped around, and while there are plenty of great cars out there (BMW 540, Lexus LS/GS 430, etc.), this one undercuts them in price- big time. Ive gotten so many compliments on its exterior, but when I take my friends for a ride, theyre all blown away. This car could easily cost $5K more based on performance alone. I was initially concerned about the turning radius, but its actually been just fine for me.

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  Todds M45 - 2006 Infiniti M45
  By Todd Bessemer - October 15 - 7:30 pm

  Great car. As good as my BMW that I traded. Only had it for 3 weeks but I cannot find a single solitary problem. Fast, Great fun to drive, gets looks and waves and beeps. Love it. Kids love the DVD player. We do too. No backseat whining from the little ones.

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  M45 OK in Richmond - 2004 Infiniti M45
  By Duane - September 20 - 10:16 pm

  Moved from an I35 to M45! Car has alot of horses! Could be a little better from the start but awesome excelleration after 55 miles an hour. Happy with the handling but could have leg room in back seat and why cant they have cruise and radio controls light up @ nite? Also they should have doors lock and unlock when moved from park. For the price they should have more standard features!

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  2006 Infinitri M45 Sport - 2006 Infiniti M45
  By Bruce Mackintosh - August 28 - 2:20 am

  All around beautifully designed and built car that seems to have it all. Quality, luxury, performance and top of the line features. Zero problems after a year of driving. I do not know what more I would want in a car, and I have had many. Excellent machine, and in its class, an excellent value.

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  awesome vehicle - 2006 Infiniti M45
  By MARK - August 2 - 3:00 pm

  I had a 2004 TL which I really liked. But, last weekend I test drove an M45 for fun and was immediately hooked on this vehicle. I traded in my TL and took over a demo with 8,000 kms on it. This vehicle is a true sports luxury vehicle. The power, handling and technology is out of this world. Even the geartronic is by far superior to my TL. The DVD audio system in my TL was the best I have ever heard until now.

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  I love My M45 SPORT - 2006 Infiniti M45
  By Brian - July 28 - 4:16 pm

  This is by far the most amazing car I have owned. I drove the BMW 545 and the Lexus GS430. Feature wise, there is no comparrison. The m45 is the fastest of the group, with the best handling, and technology. The navigation system is amazing, and the sound system is the best I have heard. The motor never quits and gets you to 60 in 5.5 seconds or under....I have been very happy so far, I owned a g35 coupe before this, and really feel that Infiniti makes quality cars that are right up there with BMW and Mercedes.

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  NICE Car Bad Back Seat - 2003 Infiniti M45
  By logan2744 - June 21 - 5:27 pm

  Purchased the car about 8 months ago. It had 124,000 miles on it. I was on a local government auction site and saw it. I wasnt even looking for a car. I was actually looking for something else not car related. It had issues. Needed paint, starter, driver seat and some tlc. I checked for recalls and found that it had 2 recalls that needed to be done. Infiniti fixed them. While at the Infiniti Shop they saw that the gas gauge wasnt working properly. That was a $1000.00+ to repair. So after getting it painted, a new driver seat, starter and putting some tlc in it at an additional cost of $1000.00+ I finally think I have a great running car. Car has some get up to it.