The Good: The 2006 Cadillac DTS is brought up-to-date with freshened styling and tightened suspension. A standard MP3 player jack in all models and XM radio in most highlight its entertainment features, with StabiliTrak and parking assistance standard on all but the base model. The Bad: With only a four-speed automatic as well as fit and finish details that aren't quite up to class standards, the Cadillac DTS is at a disadvantage. Cell phone integration is limited to the OnStar system. The Bottom Line: The Cadillac DTS improves on the DeVille it replaces with a more contemporary look and improved suspension but is held back by some lack of attention to detail and a 10-year-old power train. 2006 Cadillac DTSFor the 2006 model year, Cadillac's DeVille has morphed into the DTS. The 2006 Cadillac DTS represents more than just a change to the current Cadillac three-letter naming convention. Revisions to exterior and interior styling and a firmer, better-controlled suspension give the DTS a very different flavor than the old DeVille, even though it retains the front-wheel-drive DeVille platform. Cadillac has made a name for itself in its use of technology for its power train, suspension, safety, and entertainment systems, and the DTS is no exception. While there is one DTS body style and basic interior design, there are four trim levels: Luxury I through III and Performance. All use Cadillac's Northstar V-8 engine matched to a four-speed automatic transmission, with 275 horsepower for the Luxury models and 292 horsepower for the Performance version. Each has at least all-speed traction control, six air bags, the OnStar telematics system, advanced multizone climate-control systems, audio systems with inputs for an MP3 player, and a useful driver information center as standard equipment.Our test car came with the Luxury II package, the most value oriented. To the standard Luxury I package it adds XM Satellite Radio, memory for seats and mirrors, a heated steering wheel, the StabiliTrak system, and ultrasonic front and rear parking assist. The base price is $43,695, with $795 added for the destination charge. Options on our test car were limited to the Sun and Sound package, with a sunroof and an in-dash six CD changer for $1,795 and chrome 17-inch wheels for $795, bringing the total to $47,080.The Performance model would be of more interest to the technophile, and we had the opportunity to test it for a short time at a recent press event in the Southern California desert. With the more powerful version of the Northstar V-8 and firmer suspension tuning with Magnetic Ride Control, it has power and handling response much more in line with that of current Japanese and European luxury sedans. Many features that usually come as options on other models are included in its $50,490 base price. Recommended upgrades not on our test car include a touch-screen navigation system with voice recognition and radar-based adaptive cruise control. The 2006 Cadillac DTS with the Luxury II package includes heated and cooled front seats, with variable heat or cooling available on the backs or the backs and cushions, a pleasant feature in inclemently hot or cool weather. The front seats are soft but provide a high level of comfort and support, and they help make the DTS a fine long-distance highway cruiser. Rear-seat room is very good, with plenty of width for three passengers, and there is a central ski pass-through to the cavernous trunk. Lighters in the rear-door ashtrays can provide voltage for rear passengers, with a power point in the center console for those in front. Triple-zone climate control, including dual front with rear passenger controls at the back of the console, help keep all occupants happy. Bright interior and exterior perimeter lighting makes nighttime access safer and easier. The interior design is best described as contemporary luxury conservative and has developed from Cadillac styling over the past decade. Fit and finish, while better than in some previous Cadillacs, still lag behind the class leaders, with wide seam gaps and misalignments. The Luxury II's wood-grain trim very obviously has spent the past few million years as a petroleum product and is out of place in a car of this price. Also below class standard is the manually adjustable tilt-only steering wheel, although its cruise and auxiliary audio controls are convenient, and its heated rim is pleasant on cool days.The audio system includes an auxiliary jack for an MP3 player, set in the center stack to the lower right of the head unit.Instrumentation is complete, with the main gauges shaded from glare and backlit for easy visibility in all lighting. Controls are simple, well marked, and almost intuitive to use. The Driver Information Center (DIC) display between the speedometer and the tach is controlled by iconographic buttons to the left of the steering wheel. It can be toggled to display speed, instantaneous and average fuel economy, fuel usage, average speed, and elapsed time. Language may be set to English, German, French, Spanish, or Japanese. Interior and exterior convenience functions, including door locking, lighting control, mirror tilt when backing, and exit-seat adjustment are controlled through the DIC. Trip odometer and tire pressure can also be displayed. An analog clock, the upscale styling clich\u00e9 du jour, sits at the top of the center stack, above the audio controls. Our test car had the basic audio system, with AM, FM, and XM radio. An in-dash six-CD changer, part of the Sun and Sound package, plays MP3 CDs in addition to commercial audio discs. An unusual plus for a luxury car is a jack to connect an MP3 player or iPod. Although the standard audio system is pleasantly uncomplicated and provides very good sound quality, the display truncates the XM radio information display to 16 characters. It also displays ID3 tag information from MP3 CDs. XM reception is excellent, with very minimal signal loss or dropout from terrain or overpasses. The optional navigation system, fitted to the Performance model we drove at a GM press event, includes a bright LCD touch screen and voice-recognition technology; it's among the easier nav systems to program and use. It also significantly upgrades the XM\/MP3 interface, displaying more information than the standard audio system. Cell phone integration is through the OnStar system only. The 2006 Cadillac DTS Luxury II offers good value for its price if space is a major consideration, but it falls short in the detail execution that is expected in a car that costs more than $40,000.Big Cadillacs have always been in their element on American highways, and the 2006 Cadillac DTS doesn't disappoint. It is smooth, stable, and quiet on the freeway. Its fully independent MacPherson strut front and multilink rear suspension has good spring rates and damping for everyday driving. The Luxury package models are a bit soft to be driven aggressively but work fine at any sane pace. The computer-controlled Magnetic Ride Control (MRC) shocks of the Performance model, which vary damping rates as often as every millisecond, improve suspension response in sport-oriented driving. MRC gives ride and handling comparable to those of contemporary European luxury sedans such as the Mercedes-Benz E350, while the regular suspension is just a touch softer. Magnetically enhanced variable-assist steering gives a light touch at low speeds for easy parking, with an appropriately heavier touch for stability at higher speeds. Despite the engine's strong torque, torque steer is nearly nonexistent. Power, to the tune of 275 horsepower at 6,000rpm and 295 pound-feet of torque at 4,400rpm in the Luxury package models, comes from Cadillac's dual-overhead cam, a 32-valve aluminum-alloy Northstar V-8. Even without variable valve timing, it has great torque response from low in the power band, for effortless cruising and acceleration. The four-speed automatic would seem to be a disadvantage, given that competitive cars have five- or even seven-speed transmissions, but the Northstar's wide torque band makes up for the lack of transmission gears. Zero-to-sixty acceleration is a shade more than 7 seconds, and fuel economy is not compromised. EPA ratings are 17mpg (city) and 25mpg (highway). We averaged 22mpg overall with more than the usual amount of highway driving and saw up to a 26mpg average on the DIC readout at real-world freeway speeds. Although these numbers are relatively good, the addition of new engine efficiency technologies to the 10-year-old Northstar system could potentially wring even better numbers out of it.The 2006 Cadillac DTS's unibody structure makes use of high-strength steel for rigidity where needed and structural foam and nylon to improve crashworthiness. Front and rear crumple zones are assisted by six standard air bags: dual front, front side impact, and full-length side curtain. The dual-depth front passenger air bag deploys a large or small bag depending on impact severity, seat belt use, and seat position. Bright xenon headlights and LED taillights allow the driver to see and be seen at night, and auxiliary turn signals in the outside rearview mirrors can alert other drivers to turning intentions, although the red LEDs can be a little distracting to the DTS driver at first. Heated washer fluid should be beneficial on cold winter mornings.Cadillac was an early adopter of stability control with its StabiliTrak system, which is standard in all but the Luxury I model. Like other such systems, it uses input from the car's antilock braking and traction control systems along with data from yaw sensors and accelerometers to determine if the car is in an understeering or oversteering state. It can then activate the appropriate brakes and\/or reduce engine power to bring the vehicle back into control. It's one of the least intrusive stability-control systems, allowing spirited driving without noticeable restraint. The DTS's four-wheel antilock disc brakes feature Brake Assist for faster emergency stopping.The parking-assist lights change color from green to yellow to red as the car gets closer to an obstruction.The standard parking-assist system provides both audio and visual warning of potentially unseen obstacles. It beeps more quickly as the car gets closer to an obstruction, front or rear, and offers visual aids in the form of light displays at the top center of the dash and in the rearview mirror above the backseat. The lights change color from green to yellow to red as obstacles get closer. No backup camera is offered.GM's OnStar telematics system is standard equipment in all DTS models, with a complimentary one-year subscription to both the Virtual Advisor package, with weather, traffic, and stock information, and the Directions and Connections package, which can automatically notify the appropriate authorities of air bag deployment; provide remote unlocking, stolen vehicle location assistance, remote diagnostics, driving directions, service recommendations, directory assistance; and allow hands-free cell phone use. Though available, radar-based adaptive cruise control was not fitted to our test car.The Cadillac DTS is covered by a four-year\/50,000-mile warranty for defects in materials and workmanship. Emergency roadside assistance is provided free for any warranty-covered problem and for a nominal charge otherwise or when the car is out of warranty.