Cerberus Capital Management L.P., the New York-based privateequity company that just bought Chrysler from DaimlerChrysler AG, is off to a rousing start.

The company named as its chairman and CEO Robert Nardelli, former chief executive officer and notorious hammer of the Home Depot Inc., who recently earned glory in the annals of executive compensation when he pocketed a $210 million severance package after being kicked out by disgruntled shareholders.

Nardelli has no experience in the auto business. A company utterly besieged by bean counters has just hired Mr. Bean.

Assuming that Nardelli is more than a bagman, the question then becomes: Does he know a good car from a bad one?

I can help. I recommend he go down to the motor pool and check out the 2008 Chrysler Sebring Convertible, preferably the Limited model with the retractable hardtop. See, Bob, that's a bad one.

Not just bad, but a veritable chalice of wretchedness, a rattling, thumping, lolling tragedy of a car, a summary indictment of Chrysler's recent management and its self-eradicating product planning, all cast in plastic worthy of a Chinese water pistol.

Oh, and the Sebring Convertible is homely, too.

The Sebring Convertible has been a segment sales leader for more than a decade, in no small part because of the tens of thousands sold to the Budgets and Hertzes of the world. These were modest cars with modest ambitions - midprice, midsize, middlebrow convertibles that were comparatively well-shaped, with a low and rounded body style that looked cool with the top down.

The new-for-2008 Sebring Convertible is an open-air version of the taller, squarer Sebring sedan introduced last year. The sibling-driven proportions throw the convertible drastically out of whack. For instance, the new convertible is virtually the same length as the previous model but 3.5 inches taller. Even in our Limited edition test car with its 18-inch wheels, the wheel arches looked cavernous. To make room for the car's choice of retractable tops (in vinyl, canvas or aluminum), the convertible is 3.2 inches longer than the sedan, and all of that length is cantilevered gracelessly over the rear wheels. From some angles, the car looks like it has had unholy congress with an El Camino.

There was some effort to add surface excitement to the car - the strakes on the hood, a la the Crossfire and the exquisite Airflite concept car - but these gestures are so insincere as to be insulting.

The marketing plan is to offer the Sebring Convertible in three trims, each with its own engine: the base model ($26,145) gets the 2.4-liter, 173-horsepower four-cylinder with a four-speed automatic; the Touring ($28,745) gets the 2.7-liter V6 with 189 horsepower, also with the four-speed; the Limited ($32,345) is powered by the company's 3.5-liter V6 with 235 horsepower mated to a six-speed automatic. The retractable hardtop is a $1,995 option on the Touring and Limited.

Our nearly loaded Limited test car penciled out to $37,755, including one of the car's signature options, the MyGig audio system/navigation system with the 20GB hard drive. Other options included traction and stability control, windscreen and dual exhaust. All that easily pushes the car over the two-ton mark (base curb weight is a rather astonishing 3,959 pounds).

So configured, the Sebring Convertible muddles out of its own way. Trying to drive this car in a sporting manner feels like trying to run a 440-yard dash with a lawn tractor on your back. The car is slow to rouse, glumly servile at highway speeds, and when you kick the accelerator to pass, it is resentful to the point of gross insubordination.

Dynamically, this is certainly one of the more inept cars on the market. The steering is frictionless and void of feedback on center, vague off-center and downright enigmatic at the limit. The Sebring Limited has reasonable road holding, thanks to its 18-inch tires, but even small bumps can induce suspension-pumping body motions that can oscillate to major whoops with little provocation and send the car off course. This is purely the result of the top mechanism's barbell weight situated high in the structure.

But none of that is what really bugs me. What really bugs me is the harsh reverberation coming up through the chassis from the suspension. What, were they out of bushings that day?

The one bright spot is that the Karmann retractable hardtop mechanism works just fine (though production is being slow-walked while niggling final-fit problems are resolved). A press of a button separates the top panels and levitates them behind the rear seats. The ample trunk space is then not so ample, but Chrysler says you can get in two sets of golf clubs.

Nardelli has a conspicuous record of knowing nothing about the car business. It's a lot harder than selling Weber grills and Sawzalls. Wisdom begins with knowing the difference between a good car and a bad car. The Sebring Convertible can help.

Chrysler Sebring Convertible

Base price: $26,145.

Price, as tested: $37,755 (est.).

Power train: 3.5-liter V6; front-wheel drive; six-speed automatic.

Horsepower: 235 at 6,400 r.p.m.

Torque: 232 pound-feet at 4,000 r.p.m.

Curb weight: 3,959 pounds (base).

Wheelbase: 108.9 inches.

Overall length: 193.8 inches.

EPA fuel economy: 16 miles per gallon city, 26 m.p.g. highway.