As Cadillac has steadily improved its Cadillac CTS line-up, the interior has definitely kept pace. There are several small but welcome enhancements for 2011, including an update for GM's OnStar telematics system. With introduction of its ninth-generation control software, OnStar's voice recognition capability has been substantially improved.

Inside the CTS sedan and wagon, the basic theme is black with brushed metal and chrome accents. It's very contemporary, very attractive and generally space efficient. Optional Sapele wood, available in several packages, replaces the standard satin metallic trim. It's heavily grained, and adds a warmer, less technocratic finish.

The dashboard is fairly low and away from the front seats, leaving an airy, unhindered space in the front half of the CTS cabin. The hand-stitched center console blends seamlessly into the center stack of controls, creating a sport-cockpit ambience for the driver and front passenger, without compromising breathing space.

We found the Cadillac CTS to be a nice place to sit and take a drive. The driver feels secure and comfortable, and the front passenger enjoys a feeling of ease, confidence and luxury. Visibility in the sedan is unfettered in all directions, though in the wagon the rear glass is smaller and a bit more restrictive. It creates a narrow view through the rearview mirror.

Fortunately, a rearview camera is available for the CTS wagon. For 2011, the back-up camera is also available on the sedan, and standard on CTS-V models. The rearview camera works great on cars with navigation systems. On CTSs without navigation, the camera image is projected on a very small LED screen hidden in the rearview mirror. It's much harder to see details with the small screen.

The front bucket seats are comfortable, with enough side bolstering to keep the CTS driver snug and in place behind the wheel, even during some enthusiastic driving on central California's windiest, curviest roads. A Recaro sport seat option is available on all models, with 14 different adjustments and bolsters that can be pumped up for hard driving, then deflated for cruising. They're suitable even for race track use, but generally quite hard. Unless a driver regularly attends track events, he or she will be better served by the standard CTS seats.

We appreciated the range of adjustment with the power seats and the power steering column. The tilt-and-telescope column offers ultimate comfort and allows a proper driving position. The CTS instrument package is complete, easy to read, and graphically appealing. The center stack is particularly well done, both attractive and easy to use, with some interesting readout placements here and there. With the navigation system, and its combination of touch-screen and hard-button controls, the CTS offers one of the better driver/machine interfaces in current luxury cars.

The upgrade Bose 5.1 Cabin Surround audio system has a 40-gigabyte hard-drive for media storage, an iPod connector and USB port, and it offers the ultimate in musical enjoyment. Using the navigation screen, it's easy to switch back and forth between the three broadcast and three stored-music formats by simply touching the screen, and the blue display is large enough to be read from the back seat. It's one of the best, most fun-to-use sound systems available. In comparison, many other luxury cars have audio systems that are fussy or difficult to operate.

Cadillac CTS-V models have a few extra sporting touches inside, starting with a thick-rimmed steering wheel that can be covered with synthetic suede. It's one of our favorites in any automobile. The dead pedal, which allows the driver to brace the left leg, is great for enthusiastic driving. Subtle V badging inside reminds passengers that the owner has anted up for the super-performance package.

The rear seat offers enough room for two adults approaching six feet in height. The rear outboard seats are carved out like buckets, and quite comfortable, but the flip side is a narrow, flat plateau in the middle section. It's not a place anyone over 12 will want to sit, unless the choice is walking. A switch on the back of the center console controls airflow for rear passengers, between vents on the console itself or registers under the front seats.

The plastics on the front seatbacks and the rear end of the console form the weak link in interior finish. They're hard and not $40,000-plus in appearance. In the CTS wagon, rear-seat passengers might feel a bit more constricted due to the wide rear roof pillar extending rearward from their outboard shoulder.

With 13.6 cubic feet of luggage space, the CTS sedan's trunk is larger than those in compact luxury sedans like the or , but slightly smaller than the trunk in mid-size models like the , or .

The Cadillac CTS sport wagon delivers 53.4 cubic feet of cargo space with the seatbacks folded, 25.4 cubic feet with the rear seat in place. That's almost as much cargo space as what's found in a compact SUV.

In the wagon, the bottom of the rear seat is fixed. Yet the seatbacks fold forward easily, creating a flat load floor from almost the front seatbacks to the rear bumper, a great feature. An easy, dial-type knob allows the CTS owner to program how high the power tailgate swings open.

The carpeted floor in the wagon's cargo area slides out over the bumper, exposing a shallow, rubber-lined bin that contains water from soaked boots or coolers dripping condensation, The floor also has tie-down hooks and a slide-track system that secures various accessories. Our test car had a folding dog gate that spread floor-to-headliner behind the rear seatbacks. It was a bit of a chore to install, but once in place it was truly sturdy and impenetrable to any pet we've met.