Chrysler leading the US pack with a sporty, luxurious convertible

It's the first ''factory convertible'' in a decade - since 1971, in fact - to carry the Chrysler nameplate.

Ragtops were losing their glamour as well as profit for the US auto industry as sales fell sharply and the federal government tightened the screws on safety. Within a few years every domestic car manufacturer withdrew from the softtop business, leaving it to the specialty-conversion shops and a few imports.

Now, in its drive for the spotlight, Chrysler is back on the road with a ragtop, beating the Ford Mustang convertible by six months and the Chevrolet J-car subcompact by even more.

Both the new-for-'82 Chrysler LeBaron and Dodge 400 have their own versions of the open-top car - a reminder of the days when the convertible automobile was a reallym big seller and they were spotted throughout the product offerings from Detroit.

The new Chrysler softtop is unlike anything else on the road today. It's bigger than the Fiat X1/9 or Spider 2000, and is much heavier than the Alfa ragtop. And it certainly can't compete with the Rolls-Royce Corniche.

Simply put, it has pizazz.

Yet, the 2,800-pound car doesn't look or feel like the typical US-built convertible of the '50s and '60s, either. For one thing, like the sedan, it has front-wheel drive.

The Chrysler LeBaron and Dodge 400 softtops sport an image all their own.

In converting the 2-door coupe to a ragtop, Chrysler had to beef up the structure, including the windshield-holding-pillars and quarter panels in the rear. Low-back bucket seats are used instead of the coupe seats, thus giving more headroom inside.

Like the Ford Mustang ragtop, the Chrysler convertible is a joint effort by the car manufacturer and another Detroit-area firm, Cars & Concepts of Brighton, Mich., where the steel top is removed and the ragtop mechanism installed. The power-operated roof is controlled by a button on the console. The basic vehicle itself is built in Chrysler's St. Louis assembly plant.

The base engine is the 2.2-liter built by Chrysler, with an optional 2.6 -liter made by Chrysler's Japanese affiliate, Mitsubishi.

Indeed, the car is luxurious; the front seats provide a sporty flair and are comfortable to boot; and everything seems to work. An optional, stiffer suspension would give a more-controlled ride and provide far better handling.

Too, the base 2.2-liter engine is underpowered, and in traffic the automatic transmission shifts up and down with annoying regularity. In the vinyl-seat version without ''air'' - $12,000-plus - the only transmission is a 3-speed automatic. With air conditioning, the Mitsubishi 2.6 engine is called for.

With or without air conditioning, however, the larger engine is a must if you want any kind of performance on the road at all. Remember the big-power engines in the heyday of the softtop?

Then there's that back seat, an afterthought. ''It's the most uncomfortable seat in the world,'' snaps my 16-year-old daughter, who was relegated to the back when Mom and Dad claimed the seats up front. It's more of a 2-seater with grocery-bag space in the back.

I managed to get about 26 m.p.g. in more than a week's worth of driving over many hundreds of miles - with the smaller engine, that is.

''The convertible has held a special attraction for car lovers,'' asserts John B. Naughton, head of sales and marketing for Chrysler.

''In the absence of factory-produced convertibles, there has been a growing trend to aftermarket conversions. Chrysler is in the forefront of this returning interest.''

Chrysler will build the car entirely itself in the '83-model year.

To be inside a convertible - with the sun overhead, the wind whistling past your ears, and your eye on the road - that's fun. It reminds a more senior motorist of those softtops of years ago. And like the ragtops of memory, even the new LeBaron convertible has wind noise with the top up. But it doesn't squeak and squawk as memory reports those earlier cars did.

The new convertible from Chrysler is making history for the company as well as sales. It could hardly go wrong.