The 2008 Cadillac STS comes with a choice of V6 ($42,390) or V8 ($51,810) engines. The high-performance STS-V ($76,555) comes with a supercharged V8. All come with a six-speed automatic transmission, although the supercharged V-model uses a heavy-duty unit.

All-wheel drive is available for the V6 ($1900) and base V8 ($1550), but not the STS-V.

Standard features include leather upholstery, aluminum interior trim, dual-zone automatic climate control, Bose AM/FM/CD stereo, interior auto-dimming rearview mirror, and the usual lineup of power creature comforts and driver aids. OnStar telematics (with one year's service), StabiliTrak electronic stability control, automatic high-beam control (Intellibeam) for the headlights, and rear park assist are also standard.

The popular V6 Luxury Package ($3,540) adds two-driver memory for seats, mirrors, climate and radio controls; Rainsense wipers; six-disc in-dash CD-changer; Eucalyptus wood trim on the instrument panel, steering wheel, console and center stack; heated and ventilated front seats with four-way power lumbar; heated rear seats; heated steering wheel; tire pressure monitor, universal home remote; and a cargo net. The V6 Luxury Performance Package ($5,845) includes all of the above, plus a limited slip rear differential, Premium ZF steering gear, performance cooling package, rear spoiler, Brembo performance brakes, and P235/50R18 front tires and P255/45R18 rear tires on 18-inch polished aluminum wheels. The new Luxury Level Two Package ($705) adds Xenon HID Intellibeam headlamps with washers, a premium sound system, and navigation to V6 models with the Luxury Package.

Much of the content of the V6 Luxury Package is standard on the V8 model. The V8 Luxury Package ($4,200) adds Bose 5.1 surround sound, Xenon HID Intellibeam headlamps with washers, and heated and ventilated front seats. The V8 Luxury Performance Package ($8,190) includes all Luxury Package features plus Premium ZF steering gear, performance cooling, Magnetic Ride Control, rear spoiler, Brembo performance brakes, P235/50R18 front tires, P255/45R18 rear tires, and 18-inch polished aluminum wheels.

A new Performance Handling Package ($1,600) is available for the rear-drive V6 and both rear and all-wheel-drive V8s. It bundles StabiliTrak with the high-performance Brembo brakes and chrome-plated wheels fitted with new P255/45R18 Michelin Pilot Sport summer-only tires. On AWD V8s only, StabiliTrak includes active steering.

Standalone options for V6 and V8 models include the Bose 5.1 surround-sound stereo ($2645), premium Tuscany leather seats ($1295), a power glass sunroof ($1200) and the Brembo brakes ($395). A heads-up display (HUD) is now available on all models ($600), as is an engine block heater ($100). Some paint colors also cost extra ($995). Wood trim ($250) is available for the V6.

A new Platinum Edition features special paint, trim, wheels, and upholstery.

STS-V comes with a higher level of standard equipment, including EZ Key with remote start, XM Satellite Radio, rear AV jacks, rear climate system controls, rear obstacle detection, the Lane Departure Warning System, hand-wrapped leather seats with suede inserts, and olive ash burl wood and aluminum interior accents. Special paint and the engine block heater are the only options; the sunroof can be deleted for credit.

Safety features that come standard on all models include dual two-stage frontal airbags, front seat-mounted side airbags, and front-and-rear side curtain airbags. Four-wheel anti-lock brakes are standard, along with StabiliTrak electronic stability control. Tire-pressure monitors are standard on V8s and available as part of the Luxury package on V6s. OnStar comes standard; its operators send out the rescue squad if your airbag goes off and you don't respond to calls.

Lane Departure Warning is an optional system that uses a camera located between the inside rearview mirror and the windshield to detect lane markings on the road and alert drivers when they inadvertently stray from the lane. Side Blind Zone Alert is an optional system that uses radar sensors behind the rear fascia that signal an audible and visual alert if objects are detected where it might be difficult for the driver to see them. Adaptive cruise control with head-up display ($1695) is offered only on the V8, and enhanced StabiliTrak with active steering ($995) is available only on V8s with AWD.