The Lexus LS 460L is the best car we've seen. We can't put it any more bluntly than that. It checks off all the tech boxes, then goes and adds some new ones. The company's flagship sedan is a genius piece of work, combining technologies that contribute to a comfortable ride with the ability to tear down the roads and take the curves. And it does it all with amazingly good fuel economy, given the size of this thing and its competition.

Lexus redesigned its LS flagship for the 2007 model year, and gave it a bigger engine, more gears, and an expanded array of technology in the cabin. The automatic transmission gets eight gears to shift, more than any other production car. And this Lexus is the first car in North America to get Toyota's self-parking technology, which was previously released in the Prius for Europe and Japan. The LS comes in two basic styles, the standard LS 460 and the long-wheelbase LS 460L version. We tested the latter.

Although the LS 460L gets a long list of options and standard technology, it's not a kitchen sink kind of car. We like how everything is integrated. We like how the car drives. We like the usability of the technology. We even like the self-parking feature, which is getting backlash from other media sources.

Enough speakers for heavenly sound Our review car came with an upgraded stereo, a Mark Levinson reference system with 19 speakers. Yes, 19. We're not sure if that sets a record for a factory-installed system, but it must come close. That's six sets of two-way tweeter/midrange speakers placed along the sides of the car, one two-way in the dash for center fill, big woofers in each door, and a subwoofer in back. These speakers get 450 watts from 15 channels pumped through them. The result is near-perfect audio quality. We used various audio sources and different types of music in our testing, and the system created a nice surround effect while producing excellent separation and clarity with each one. Bass came through strong, while the highest notes still stood out. With the digital signal processor placing the sweet spot for the music dead center in the cabin, the audio actually sounded best in the back seat.

But that's not all we have to say about this audio system. It has a hard drive. Actually, the main purpose of the hard drive is to store data for the navigation system. But there's 8GB left over that can be used for MP3s. Better yet, the system can be set to rip any CD that's put into the changer at either 256Kbps or 128Kbps. The system has the Gracenote CD database built in and will automatically recognize CDs and apply ID3 tags to the ripped tracks. We like this a lot. We ripped six CDs to the system, and it told us we had used 3 percent of the hard drive space. Although 8GB isn't huge by today's standards, it's enough to carry around an adequate music library. The management screen for the hard drive is fairly easy to use, although it does require pushing a button labeled Play mode to change from artist to album selection. We liked the music-management screen on the Cadillac Escalade EXT a bit better.

The LS 460L's stereo can handle other audio sources, as well. It has a six-CD changer that can also read audio and video DVDs. Our car didn't have a rear-seat entertainment system, although that is an option, but we could watch DVDs on the car's dashboard LCD. It also has an auxiliary audio input, for MP3 players, and comes with XM satellite radio. We found it easy to navigate the XM radio channels, using the touch screen to select a category and the tuning knob to choose a station within the category.

Having XM satellite radio is important because the car's navigation system has live traffic reporting, an XM service. We've previously seen this type of live traffic reporting in the RDX. The system overlays traffic information on the navigation map, showing traffic flow in red, yellow, or green for freeways and specific incidents as yellow icons. The system only shows traffic in specific metropolitan areas, and only for major roads, such as freeways or highways. We were impressed that the system in the LS 460L spoke up when there was an incident along the route we had programmed, informing us of an accident 15 miles ahead. It gave us plenty of time to take an exit from the freeway and bypass the accident. The system can also be set to automatically route around incidents. In our testing we did notice some bad reporting, mostly showing green lines on the freeway, indicating free-flowing traffic, while traffic was moving less than 40mph. But that's a fault of the traffic-reporting infrastructure more than the in-car system.

Otherwise, the navigation system worked well. The screen was big, bright, and easy to read. The destination input screen is well-designed, both for aesthetics and usability. Its points-of-interest database is complete, including the usual restaurants, parking, gas stations, and ATMs, along with retail stores. And because it's a hard drive-based system, response times are faster than with a DVD. Route guidance is also very good, although the voice prompts can't read out names of individual streets. When the car approaches an upcoming turn on the route, the map goes to a split screen, showing the map on one side and a graphic of the turn on the other. Accuracy was very good in our testing, even among tall buildings.

At this level of luxury, a voice command system is to be expected. In our testing with the LS 460L, it generally worked very well. It let us input destinations, recognizing every part of the address we spoke. We did find that we had to pronounce Rodeo Drive as ro-dee-o instead of ro-day-o. It also accepts commands for the audio system and Bluetooth cell phone integration. The phone system also worked very smoothly, letting us pair our phone up without a hitch. Even better, once the phone was initially paired, it immediately linked up with the phone again whenever we were in range (as long as our phone's Bluetooth transmitter was on). The car can copy over a phone's address book, up to 1,000 entries, although every time we tried it with our Motorola V551, it broke the Bluetooth connection.

But the feature that everyone is talking about, the one that invites awe at its technical wizardry or disdain for catering to less skilled drivers, is the parking assistant. The car can steer itself into parallel or slotted parking places. If the car has possible parking places around it and it's put into reverse, buttons appear on the touch screen that lets the driver choose parallel or slotted parking. Once the car is in self-parking mode, a green frame settles on the most likely parking spot, and arrow buttons let the driver adjust the positioning of the spot. Once the spot is chosen, the driver just needs to control the brake while the car steers itself back into the parking spot.

In our testing of the system, we found it identified a valid parking spot very quickly if we had the car positioned properly. For parallel parking, the driver's seat should be next to the front bumper of the car the Lexus is intended to park behind. We found the system works best if the curb is of normal height and there are cars in front and back of the space. Identifying a valid parking space is the biggest challenge--once it's set, the car steers itself right in. We were particularly impressed when the car put itself into a relatively tight spot. When we tried to park in a slotted spot with no cars to either side, we had to spend more time adjusting the green frame, but the car smoothly put itself into the spot. Overall, we like this feature. Although it didn't work under all circumstances, it worked in more than we would have expected.

The materials in the cabin are very luxurious. Lexus' press kit on the car points out that all interior wood comes from a single tree, just to ensure that all the grain matches. We are also impressed with the interior lighting, which uses LED spots for each seat, making it possible for a passenger to read a book without interfering with the driver's night vision.

Eight gears to choose from Although the cabin of the LS 460L is impressive, Lexus doesn't skimp on the drivetrain, either. The automatic transmission has eight gears. And that's not just excess, as this transmission is pretty smart. In our test driving, shifts were smooth, and most of the time not even noticeable. When we needed power, the transmission was there for us. When going downhill, the transmission downshifted to add a little engine braking. When the transmission is in Drive mode, it uses all gears, but in its Sport mode it tops out at six. It also offers manual selection, where the whole range is available.

The LS 460L's main competitor, the Mercedes-Benz S550, only has seven gears, but it has a bigger engine. As the name would suggest, the LS 460L is powered by a 4.6-liter V-8 producing 380 horsepower. But the S550's bigger engine only seems to get worse gas mileage, as the LS 460L gets to 60mph in 5.4 seconds, whereas the S550 takes 6.14 seconds. We found the engine to be more than adequate to move this big car around, pushing it up hills and off the line without complaints or hesitation. Better yet, the EPA mileage on the LS 460L is 18mpg in the city and 27mpg on the highway. In our testing, which was biased toward highway driving, we observed 24mpg. Those are very good numbers for a big car with a relatively big V-8.

The S550 had a slightly more comfortable suspension than the LS 460L, making the Lexus the second best we've ever tested. It floats over potholes and road imperfections, quickly damping out jolts. There is an air suspension option available that may produce an even better ride, but our test car was not so equipped.

Handling is also good on this car. At low speeds the steering is fairly light, but it firms up underway. It is a fairly big car, and we felt that weight on the curves, but the tires stayed firmly on the road. It's helped along by Lexus' version of stability control, VDIM, which stands for vehicle dynamics integrated management. VDIM takes into account lots of vehicle data, such as wheel slip, deceleration, braking, and speed to provide a smoother driving experience than standard stability control systems.

Four braking system acronyms The LS 460L also has an extensive array of braking technologies designed for safety and handling that go under various acronyms, such as ECB (electronically controlled braking), ABS (anti-lock braking system), EBD (electronic brakeforce distribution), and BA (brake assist). In our use, we always found the brakes responsive, without being too grippy. Even the parking brake is electronic.

Air bag coverage in the LS 460L is more than complete. The driver and front passenger get front air bags, side air bags, and knee air bags, while side curtain air bags run from front to back. Our car also had optional rear-seat side air bags. Lexus Link telematic service is also available, which will automatically send out an emergency signal if air bags are deployed. The car hasn't been rated by the NHTSA for crash protection yet.

A couple of other nice features worth mentioning are the tire pressure monitor and hill hold. Tire pressures are shown on the instrument cluster display, and even include the pressure in the spare. Hill hold is activated by pushing a button on the steering wheel. When it's activated, the car won't roll when the brake pedal is released.

The Lexus warranty offers four years or 50,000 miles of basic coverage, and six years or 70,000 miles of powertrain coverage.

Our review car was the 2007 Lexus LS 460L, with a base price of $71,000. It had a luxury package ($2,780) that added power rear seats and other options, the Mark Levinson stereo upgrade ($2,530), Lexus Link telematic service ($900), Intuitive Parking Assist ($500), and the whiz bang Advanced Parking Guidance System ($700). With the destination charge, the total came out to $79,125.

The near-$80,000 price tag is hefty, but it's substantially cheaper than the Mercedes-Benz S550 or the BMW 750Li. Its fuel economy is also substantially better than these competitors, which makes it a compelling choice in this segment. But if the price of the LS 460L still sounds on the high side, $10,000 can be quickly shaved off with the standard wheelbase LS 460, which has a base price of $60,000.