When is a car retro without trying to be retro? When it's the 2008 Mercury Grand Marquis. Based on an automotive platform design that dates back about 30 years, the Marquis features rear-wheel drive, a live rear axle and body-on-frame construction -- the latter of which is a design attribute kept alive in modern cars solely by the Grand Marquis and its relatives.

This old-school approach to car design does have a few benefits, namely its robust simplicity and cheap maintenance costs (which, naturally, make it a favorite of the nation's livery and law enforcement communities). But there's a reason other full-size cars are no longer built like this big old Merc -- actually, there are quite a few reasons. More modern competitors offer just as much interior room, and they deliver it in a more stylish, functional package. And by virtue of their more sophisticated engineering, most offer a vastly superior driving experience.

For non-fleet buyers, the 2008 Grand Marquis' principal selling points are its ample size, rock-solid safety performance and relatively low price. Anyone in this country who has at some point ridden in the backseat of a Grand Marquis or Crown Victoria taxi (or perhaps a cop car) knows how large the interior and trunk are. Hip and shoulder room are particularly impressive thanks to the ultra-wide body.

But compare the Grand Marquis to Mercury's own full-size '08 Sable (formerly the Montego) for instance, and the advantages fade away. The Sable's trunk is a tad larger; its rear-seat head- and legroom are more generous; and its crash test scores are identical -- in fact, IIHS rated it as a top safety pick. Plus, the Sable's about the same price, has a similarly powerful but more fuel-efficient V6 engine and a higher-quality interior, drives substantially better and has a wider array of available features. Notice a pattern?

The 2008 Mercury Grand Marquis' longtime platform-mate, the Ford Crown Victoria, is now sold only to fleet buyers. That means regular folks who still want one of these automotive relics must stick with the Grand Marquis or the more expensive Lincoln Town Car. Although the Mercury has some limited appeal, we simply cannot recommend it when there are other full-size sedans that meet or vastly outdistance the Grand Marquis. In addition to the Sable and the nearly identical Ford Taurus, other large sedans like the Chrysler 300, Hyundai Azera and Toyota Avalon are much better choices.

The 2008 Mercury Grand Marquis is a full-size sedan available in two trim levels -- GS and LS. Base GS models come with 16-inch steel wheels with faux chrome wheel covers, air-conditioning, a CD player, a front bench seat with power adjustments for the driver, cruise control, automatic headlamps, full power accessories and keypad entry. The Grand Marquis LS adds 16-inch alloy wheels, foglights, automatic climate control, leather upholstery, power seat adjustments for the front passenger, a leather-wrapped steering wheel, a rear-seat fold-down armrest, an auto-dimming rearview mirror, heated side mirrors and an overhead console with a compass and Homelink garage door opener.

On the options list for the LS, you'll find stand-alone items like a sunroof, heated front seats and an upgraded audio system with a CD changer. The Palm Beach Edition Package includes chrome wheels, chrome-trimmed mirrors, cashmere leather seats embroidered with "Palm Beach" logos and satin-finish metallic interior trim. A rear air suspension is optional on both GS and LS trim levels.

Only one engine and transmission are offered on the Grand Marquis: a 4.6-liter V8 coupled to a four-speed automatic that sends 224 horsepower and 275 pound-feet of torque to the rear wheels. Fuel economy is on par with other large V8-powered sedans, with 2008 EPA estimates at 15 mpg city/23 mpg highway. However, those competitors offer much more horsepower.

Antilock disc brakes are standard on every 2008 Mercury Grand Marquis, while traction control is optional on the GS and standard on the LS. Power-adjustable pedals and front seat-mounted side airbags are optional on the LS, but side curtain airbags and stability control are not available on any Grand Marquis.

Despite missing a few safety features, the Grand Marquis nevertheless has scored well in tests by the National Highway Traffic Safety Administration. It rates a perfect five stars in frontal-impact crash protection and, when equipped with side airbags, it earns five stars for front and rear side-impact safety as well. (Without the bags, it gets four stars.) The big Mercury sedan also earned the top rating of "Good" in frontal-offset crash testing conducted by the Insurance Institute for Highway Safety.

Like the interior, driving the 2008 Mercury Grand Marquis is none too different from piloting one from 15 years ago…or even 15 years before that. Due to the vehicle's size, pillow-like suspension and low-effort steering, it has all the road feel of a two-mast schooner. These may seem like positives to some folks, but quite simply, newer full-size sedans are easier to maneuver and better to drive, while still offering safe structures and comfortable rides. On the upside, the standard V8 provides plenty of acceleration for any situation, particularly on the highway where the Grand Marquis is best suited.

The Grand Marquis has a wide, spacious interior that can seat up to six in a pinch. Nevertheless, the rear seat is matched or surpassed in roominess by newer, better-driving full-size sedans. Controls and instruments are simple and easy to decipher, but the overall design is dated. The trunk is quite large, with 20.6 cubic feet of space capable of swallowing copious amounts of luggage or several sets of golf clubs.