Because the North American luxury car market encompasses a vast range of automobiles priced from under $30,000 to sky’s the limit, it’s helpful to break the segment into easily digestible chunks. Most commonly, we call those chunks entry luxury, mid-luxury, super-luxury, and ultra-luxury. Entry luxury cars usually cost between $25,000 and $40,000, and they don’t always have a luxury brand attached to them. Mid-luxury cars typically run between $40,000 and $60,000, and always carry a nameplate that resonates with image-conscious Americans. Super-luxury cars cost upwards of $60,000 but less than $100,000, and inspire envy in both friends and enemies. Ultra-luxury cars are six-figure expenses guaranteed to land the hottest date in town and the best parking spaces at the trendiest nightspots.

For this comparison test, we selected three mid-luxury models from Japan that have been completely redesigned for the 2005 or 2006 model years. And because one competitor, the Acura RL, comes only with a V6 engine and an all-wheel-drive system, that’s how we configured each test car to eliminate any potential for unfair advantage. Each model came standard with power windows, locks, mirrors, and seats. They also came equipped with Bluetooth wireless communications technology, keyless ignition and locking systems, six airbags (front, side, and curtain), and stability control. Here’s a closer look at the Acura RL, Infiniti M35x, and Lexus GS 300 AWD:

2005 Acura RL
Acura, a division of Honda, was the first Japanese luxury brand out of the gates, landing on U.S. soil for 1986. Its flagship at the time was the Legend, which came in coupe and sedan formats. The Legend became a hit, got a redesign for 1991 to battle newcomers from Infiniti and Lexus, and then died when the 1996 3.5 RL sedan came along to replace it. The 3.5 RL lacked brand recognition and was blandly styled. Plus, it was front-wheel drive with a V6 engine while rapidly improving competitors offered rear-wheel drive and a V8. Nevertheless, the 3.5 RL lasted well beyond its expiration date, until the redesigned 2005 RL arrived.

The 2005 Acura RL still has a V6 under the hood, but that V6 whips up 300 horsepower and is connected to a slick Super Handling All-Wheel-Drive (SH-AWD) system. Other standard highlights include an Active Front Lighting System (AFS) that swivels the xenon headlights to see around curves, an Acura/Bose surround sound system with DVD audio and AudioPilot active noise cancellation, a one-year subscription to XM satellite radio, AcuraLink communications with real-time traffic reporting, and a navigation system with voice recognition capability. The RL also includes a power rear sunshade and a power moonroof. Not bad for just $49,715, including the $615 destination charge.

For 2006, Acura offers a new Technology Package for the RL. It includes a Collision Mitigation Braking System (CMBS) that can identify potential crashes and warn the driver to take action. If the driver fails to take action, the RL will automatically tighten the front seatbelts and apply braking pressure to reduce speed before impact. The Technology Package also includes an Active Cruise Control (ACC) system and Michelin PAX run-flat tires that can go up to 125 miles at 50 mph when air pressure is lost. Acura says the Technology Package will add about $4,000 to the price of the RL. Prices for 2006 were not final when this story was published, but we expect a loaded ’06 RL to run less than $55,000.

2006 Infiniti M35x
Nissan’s Infiniti and Toyota’s Lexus nameplates arrived in America at about the same time, with limited lineups for the 1990 model year, but the cushier Lexus models proved more popular with consumers. Whether Infiniti’s sales stumble was due to its emphasis on Euro-style performance while Lexus chose to combine Cadillac décor with Mercedes styling and Toyota reliability, or because of the infamous Infiniti “rocks and trees” advertising launch, is unclear. What is clear is that the original M30 coupe and convertible weren’t huge hits and didn’t last long. In fact, the “M” designation took a decade off, re-emerging for 2003 as a loved-or-loathed sports sedan to plug the gaping hole between the successful new G35 entry-luxury model and the faltering Q45 flagship sedan.

For 2006, a new M debuts, taking its design cues from the smaller G35 and the larger Q45, slotting neatly into the lineup between the two. Offered with a choice between V6 or V8 power, rear- or all-wheel drive, and in regular-strength or sport-tuned guise, the 2006 Infiniti M is an impressive piece of work. Our M35x test car came with a 280-horsepower V6 and all-wheel-drive, connected to a five-speed automatic with a cool rev-matching blip on downshifts. Appealing options include climate-controlled front seats, a Bose Studio Surround audio system, a navigation system with voice recognition capability, a rearview monitor that displays objects behind the car on the navigation system screen, Intelligent Cruise Control (ICC), a Lane Departure Warning (LDW) system, and a rear-seat DVD entertainment system.

Our test car started at $43,140 including a $610 destination charge, and added the $2,750 Journey Package and the $4,200 Technology Package, for a grand total of $50,700. The Journey Package includes Bose speakers, the rearview monitor, xenon auto-leveling headlights with Adaptive Front Lighting System (AFS), climate-controlled front seats, pre-crash seatbelt technology, and a HomeLink universal transmitter. The Technology Package adds the Bose Studio Surround sound system, a navigation system, ICC, LDW, and Sirius satellite radio.

2006 Lexus GS 300 AWD
Like Infiniti, the Lexus lineup was small upon debut in 1990, but it didn’t take long for new models to arrive. The first Giugiaro-designed GS debuted for 1993, looking like nothing else on the road and finding an instant customer base between the Camry-derived ES 300 and the incredibly refined LS 400 flagship. The GS was Lexus’ first crack at a sports sedan, and though the company continues to try and find the right balance between performance and luxury, the redesigned 2006 GS is one of its best attempts yet. For 2006, it’s offered with either a V6 or V8 engine, driving the rear or all four wheels.

We selected the GS 300 AWD for this test, which includes a 245-horsepower V6 and starts at $45,100 including the $650 destination charge. Interesting standard features include water repellent front door glass and a power trunk closer. Key options are an amazing Mark Levinson audio system, an Adaptive Front Lighting System (AFS), rain-sensing wipers, park assist sensors, a navigation system, a back-up camera, a rear sunshade, XM satellite radio, and ventilated front seats. A Pre-Collision System (PCS) is also optional for nearly $3,000, and it can detect a collision before it occurs. When a crash is about to happen, PCS will automatically tighten the front seatbelts and prepare the brake assist system to engage full braking power the moment the driver jams on the brake pedal. A Dynamic Cruise Control system is included with the PCS.

Our test car was equipped with the package that includes the Mark Levinson audio system and the navigation system, as well as a power moonroof, a power rear sunshade, park assist sensors, XM satellite radio, ventilated front seats, and rain-sensing wipers with AFS for an out-the-door price of $52,701.