The Good: Powerful V-8; world-class audio; automatic cruise control; heads-up display; bristles with technology. The Bad: Expensive; absurd fuel economy and range; blind spot; interior plastics; some gadgets are too much. The Bottom Line: It may be expensive, and it may gulp gas, but the Cadillac STS features all the power you could want, as well as a slew of gadgets for making driving easier, safer, and fun. 2005 Cadillac STSOne look at the 2005 Cadillac STS, and you know why it's General Motor's flagship sedan and technological showpiece. Amid GM's lackluster lineup, layoffs, and continuing financial problems, the STS shines with its digital luxuries and power and has the makings of a genuine sales hit. More than a mere car for getting from here to there, the STS is an awesome display of technological mastery that's meant to show off Cadillac's skills at making the driver feel at home, safe, and in control. With a 320-horsepower V-8 engine, sophisticated all-wheel drive, radar-based cruise control, and a heads-up display that projects vital information on to the inside of the windshield, the Cadillac STS is the closest thing to an American supercar. \r\n\r\nHowever, there's a big trade-off for all this engineering excellence: price. The $47,000 base price is just the start. Our test model had the $13,115 package, which includes everything from leather seats to XM Radio to 18-inch aluminum wheels, as well as the $2,300 cruise control, $1,900 all-wheel drive, and $995 paint job. Tack on the $1,000 gas-guzzler tax and GM's $695 delivery charge, and you're looking at a total of around $70,000. This puts it on a par with the similarly equipped Mercedes E350 but outpaces the more powerful by over $10,000. In addition, the Cadillac STS guzzles gas and has a disappointingly short range between fill-ups.\r\n If the thought of Cadillacs brings chrome-laden land yachts to mind, think again, because the 2005 Cadillac STS is not only one of the most powerful cars you can buy but also one that tempers raw power with advanced technologies to keep it comfortable, safe, and under control at all times. Front and center is the car's 8-inch control screen, which is bright and visible from the passenger seat; plus, it can be tilted to three vertical angles to avoid being overwhelmed by sunshine. Unlike with most cars, you can play DVD movies on it (but only when parked), and there's a set of video-input jacks for connecting an external player. \r\n\r\nAside from viewing DVDs, you can make good use of the display with the STS's GPS navigation system. We really like the 3D bird's-eye road view and the built-in compass, as well as the dual-mode screen, which gives you both an overview and close-ups. The system also has first-rate predictive entry and lets you choose different routes. That said, we did have a couple of complaints. There is no joystick for working with the maps, and the synthesized male or female voice prompts sound sterile. Like many other luxury sedans, the 2005 Cadillac STS features a voice-recognition system, but it gets confused. For example, when we said "Set temperature 65," the car responded with "Select CD."\r\n\r\nThe optional Bose 5.1 surround-sound system adds 15 speakers throughout the car, including 2 on top of each front seat, to make for a first-rate stereo experience, pumping out enough volume for overpowering a ghetto blaster and providing excellent balance between bass and midrange tones. We really like the heated steering wheel's volume and track buttons for AM, FM, and XM satellite radio, as well as the ability to listen to CDs and MP3s. The disc jockey can hold six CDs but takes a frustrating half-minute to get started or give up a disc. The optional stereo also adds Bluetooth for turning the STS into a phone booth on wheels. Meanwhile, the OnStar system is part of the standard package and allows for emergency calls or just asking for directions.\r\n\r\nDespite being one of GM's most expensive cars, the 2005 Cadillac STS has a plastic dashboard and door inserts that are more fitting for an economy car that's one-quarter the cost. However, the excellent floating-analog gauges show speed, temperature, engine speed, and fuel; plus, digital readouts display secondary data. In terms of other tech, the key fob is one of the STS's coolest tricks, and it can do away with a physical key, although one is included. It can remotely start the car from 300 feet away or fire it up from inside with the circular button, which is to the right of the steering wheel. The car also smartly detects the fob from a meter away and automatically unlocks the door as you pull the handle. \r\n\r\nOur test model came with motorized leather seats that can be heated and cooled, and even though the latter feels a little creepy at first, it is essential on hot days. The trunk is spacious but short and is better for groceries than a computer or TV. Long items, such as skis, fit through a door in the middle of the backseat, but the car's thick pillars make for a nasty blind spot over the driver's left shoulder. \r\n Although you can opt for a 217-horsepower V-6 engine, the heart of the 2005 Cadillac STS is its aluminum, 4.6-liter Northstar V-8 engine. There's variable valve timing for peak performance, but it remains calm at idle, then revs freely to smoothly pump out 320 horsepower at 6,400rpm with the snarl of a leopard. Our all-wheel-drive STS model came with a five-speed automatic transmission that has a manual shift option; you can just slide the shifter to the right and click it up and down through the gears. It all adds up to an exhilarating 6-second, 0-to-60mph time, which puts the STS on a par with the BMW 7 Series and Mercedes-Benz E-Class luxury sedans. Better yet, for those who get anxious when passing a truck, the STS can go from 30mph to 50mph in a speedy 1.3 seconds, although it is an isolation zone on the inside, registering a quiet 63dBA at 60mph.\r\n\r\nUnder the skin is GM's Sigma platform, which is used in and SRX vehicles. The sophisticated suspension features shock absorbers that have oppositely oriented electromagnets for delivering a good balance between precise handling and a comfortable ride. The result is a car that tracks well regardless of the road surface. Our only qualm is that while the optional ZF-made steering rack delivers tight turning for parking, it requires near-constant input at highway speeds. With four-wheel disc brakes, the STS stops straight with a minimum of ABS chatter.\r\n\r\nAs good as it is, at 4,230 pounds, the 2005 Cadillac STS is too muscle-bound for life in a world of $50 fill-ups. Its real-world fuel economy of 14.5mpg over 400 miles of city and rural driving is absurd, as is the $1,000 gas-guzzler tax and 250-mile range. Those who like to do repairs themselves will be frustrated because the engine offers little in the way of access. Sure, you can check the oil and windshield cleaner, but just about everything else is covered by black plastic trim. \r\n\r\nWithout a doubt, the combination of the car's heads-up display (HUD) and adaptive cruise control is a techno tour de force. The HUD projects key data on to the windshield, where the driver can see it without refocusing. Speed is always there, but driving directions, climate-control changes, and a CD track are added as needed. The four-color display is always visible, but the glass annoyingly reflects the dashboard. Meanwhile, the 2005 Cadillac STS has the best cruise control on the road, with a radar receiver in the grille that maintains constant spacing between cars. It, however, sometimes mistakenly picks up a vehicle in the next lane.\r\n About the only safety trick that the 2005 Cadillac STS misses is that, unlike the Infiniti M45, it lacks a backup camera to display what's behind you as you're reversing the vehicle. However, the STS will warn you when the car gets too close to an object with a beeping sound, so you'll never scratch its bumper when parallel parking. Other safety features include automatic rain sensors, an autodimming rearview mirror, Intellibeam headlights that turn on the high beams, and a nifty tire gauge that monitors pressure and warns you if a tire is going flat. We enjoyed all these tech luxuries, but sometimes the STS goes too far, with side-view mirrors that tilt down and inward to help you back up and scan for obstructions, such as children or sneaky garbage cans. It ends up being more annoying than helpful. Still, this is one safe car: It has front and side air bags for the driver and passenger, as well as curtain bags all around. Oddly, the National Highway Traffic Safety Administration has not rated the STS for crash worthiness and occupant protection.\r\n\r\nCadillac is up to date with an excellent owner's Web site that has personalized warranty information, online manuals, recalls, and current trade-in values. GM covers the car for four years\/50,000 miles and includes roadside service.